From 826484e15d7d638573eed914571b1cf11345fd8b Mon Sep 17 00:00:00 2001 From: Libin YANG Date: Fri, 21 Mar 2025 20:22:54 +0800 Subject: [PATCH] feat: update lc problems --- .../0100-0199/0195.Tenth Line/README_EN.md | 15 ++ .../0486.Predict the Winner/Solution.rs | 4 +- .../0799.Champagne Tower/README_EN.md | 20 +- .../1108.Defanging an IP Address/README_EN.md | 13 +- .../README_EN.md | 20 +- .../1138.Alphabet Board Path/README_EN.md | 32 ++- .../README_EN.md | 18 +- .../README_EN.md | 26 +- .../README_EN.md | 28 ++- .../1200-1299/1256.Encode Number/README_EN.md | 12 +- .../README_EN.md | 16 +- .../README_EN.md | 22 +- .../1324.Print Words Vertically/README_EN.md | 31 ++- .../README.md | 233 +++++++++++++---- .../README_EN.md | 235 ++++++++++++++---- .../Solution.cpp | 36 +-- .../Solution.cs | 26 ++ .../Solution.go | 28 +++ .../Solution.java | 24 +- .../Solution.js | 30 ++- .../Solution.py | 22 +- .../Solution.rs | 31 +++ .../Solution.ts | 21 +- .../README_EN.md | 39 ++- .../README_EN.md | 22 +- .../1470.Shuffle the Array/README_EN.md | 22 +- .../README_EN.md | 20 +- .../README_EN.md | 12 +- .../1534.Count Good Triplets/README_EN.md | 33 ++- .../README_EN.md | 31 ++- .../README_EN.md | 49 +++- .../README_EN.md | 40 ++- .../README_EN.md | 49 +++- .../1660.Correct a Binary Tree/README_EN.md | 42 +++- .../README_EN.md | 23 +- .../README_EN.md | 15 +- .../README_EN.md | 30 ++- .../README_EN.md | 30 ++- .../README_EN.md | 51 +++- .../README_EN.md | 33 ++- .../README_EN.md | 18 +- .../README_EN.md | 26 +- .../README_EN.md | 27 +- .../README_EN.md | 29 ++- .../1872.Stone Game VIII/README_EN.md | 45 +++- .../README_EN.md | 24 +- .../README_EN.md | 36 ++- .../README_EN.md | 26 +- .../README_EN.md | 23 +- .../README_EN.md | 34 ++- .../README_EN.md | 40 ++- .../README_EN.md | 36 ++- .../2612.Minimum Reverse Operations/README.md | 81 +++--- 53 files changed, 1578 insertions(+), 351 deletions(-) create mode 100644 solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cs create mode 100644 solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.go create mode 100644 solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.rs diff --git a/solution/0100-0199/0195.Tenth Line/README_EN.md b/solution/0100-0199/0195.Tenth Line/README_EN.md index 7ca9f7187d210..69bdfb2395242 100644 --- a/solution/0100-0199/0195.Tenth Line/README_EN.md +++ b/solution/0100-0199/0195.Tenth Line/README_EN.md @@ -23,26 +23,41 @@ tags:

Assume that file.txt has the following content:

+
 Line 1
+
 Line 2
+
 Line 3
+
 Line 4
+
 Line 5
+
 Line 6
+
 Line 7
+
 Line 8
+
 Line 9
+
 Line 10
+

Your script should output the tenth line, which is:

+
 Line 10
+
Note:
+ 1. If the file contains less than 10 lines, what should you output?
+ 2. There's at least three different solutions. Try to explore all possibilities.
diff --git a/solution/0400-0499/0486.Predict the Winner/Solution.rs b/solution/0400-0499/0486.Predict the Winner/Solution.rs index ed4b4f70ffb58..5757d0ae3acb5 100644 --- a/solution/0400-0499/0486.Predict the Winner/Solution.rs +++ b/solution/0400-0499/0486.Predict the Winner/Solution.rs @@ -13,8 +13,8 @@ impl Solution { return f[i][j]; } f[i][j] = std::cmp::max( - nums[i] - Self::dfs(nums, f, i + 1, j), - nums[j] - Self::dfs(nums, f, i, j - 1) + nums[i] - Self::dfs(nums, f, i + 1, j), + nums[j] - Self::dfs(nums, f, i, j - 1), ); f[i][j] } diff --git a/solution/0700-0799/0799.Champagne Tower/README_EN.md b/solution/0700-0799/0799.Champagne Tower/README_EN.md index 7c1df1e554754..c04fa21334900 100644 --- a/solution/0700-0799/0799.Champagne Tower/README_EN.md +++ b/solution/0700-0799/0799.Champagne Tower/README_EN.md @@ -27,35 +27,51 @@ tags:

Now after pouring some non-negative integer cups of champagne, return how full the jth glass in the ith row is (both i and j are 0-indexed.)

 

+

Example 1:

+
 Input: poured = 1, query_row = 1, query_glass = 1
+
 Output: 0.00000
+
 Explanation: We poured 1 cup of champange to the top glass of the tower (which is indexed as (0, 0)). There will be no excess liquid so all the glasses under the top glass will remain empty.
+

Example 2:

+
 Input: poured = 2, query_row = 1, query_glass = 1
+
 Output: 0.50000
+
 Explanation: We poured 2 cups of champange to the top glass of the tower (which is indexed as (0, 0)). There is one cup of excess liquid. The glass indexed as (1, 0) and the glass indexed as (1, 1) will share the excess liquid equally, and each will get half cup of champange.
+

Example 3:

+
 Input: poured = 100000009, query_row = 33, query_glass = 17
+
 Output: 1.00000
+

 

+

Constraints:

diff --git a/solution/1100-1199/1108.Defanging an IP Address/README_EN.md b/solution/1100-1199/1108.Defanging an IP Address/README_EN.md index d141c92ba6e45..537e7be2aa54c 100644 --- a/solution/1100-1199/1108.Defanging an IP Address/README_EN.md +++ b/solution/1100-1199/1108.Defanging an IP Address/README_EN.md @@ -23,18 +23,29 @@ tags:

A defanged IP address replaces every period "." with "[.]".

 

+

Example 1:

+ 
Input: address = "1.1.1.1"
+
 Output: "1[.]1[.]1[.]1"
+

Example 2:

+ 
Input: address = "255.100.50.0"
+
 Output: "255[.]100[.]50[.]0"
+
+

 

+

Constraints:

diff --git a/solution/1100-1199/1111.Maximum Nesting Depth of Two Valid Parentheses Strings/README_EN.md b/solution/1100-1199/1111.Maximum Nesting Depth of Two Valid Parentheses Strings/README_EN.md index c9697163bc163..f4d4f5e49c794 100644 --- a/solution/1100-1199/1111.Maximum Nesting Depth of Two Valid Parentheses Strings/README_EN.md +++ b/solution/1100-1199/1111.Maximum Nesting Depth of Two Valid Parentheses Strings/README_EN.md @@ -22,17 +22,25 @@ tags:

A string is a valid parentheses string (denoted VPS) if and only if it consists of "(" and ")" characters only, and:

We can similarly define the nesting depth depth(S) of any VPS S as follows:

For example,  "", "()()", and "()(()())" are VPS's (with nesting depths 0, 1, and 2), and ")(" and "(()" are not VPS's.

diff --git a/solution/1100-1199/1138.Alphabet Board Path/README_EN.md b/solution/1100-1199/1138.Alphabet Board Path/README_EN.md index 985ac691f6ce8..27f26e711961c 100644 --- a/solution/1100-1199/1138.Alphabet Board Path/README_EN.md +++ b/solution/1100-1199/1138.Alphabet Board Path/README_EN.md @@ -28,11 +28,17 @@ tags:

We may make the following moves:

(Here, the only positions that exist on the board are positions with letters on them.)

@@ -40,19 +46,31 @@ tags:

Return a sequence of moves that makes our answer equal to target in the minimum number of moves.  You may return any path that does so.

 

+

Example 1:

+ 
Input: target = "leet"
+
 Output: "DDR!UURRR!!DDD!"
+

Example 2:

+ 
Input: target = "code"
+
 Output: "RR!DDRR!UUL!R!"
+
+

 

+

Constraints:

diff --git a/solution/1100-1199/1139.Largest 1-Bordered Square/README_EN.md b/solution/1100-1199/1139.Largest 1-Bordered Square/README_EN.md index 0e417fbc50b55..f88d6f213fbf6 100644 --- a/solution/1100-1199/1139.Largest 1-Bordered Square/README_EN.md +++ b/solution/1100-1199/1139.Largest 1-Bordered Square/README_EN.md @@ -23,27 +23,39 @@ tags:

Given a 2D grid of 0s and 1s, return the number of elements in the largest square subgrid that has all 1s on its border, or 0 if such a subgrid doesn't exist in the grid.

 

+

Example 1:

+
 Input: grid = [[1,1,1],[1,0,1],[1,1,1]]
+
 Output: 9
+

Example 2:

+
 Input: grid = [[1,1,0,0]]
+
 Output: 1
+

 

+

Constraints:

diff --git a/solution/1100-1199/1184.Distance Between Bus Stops/README_EN.md b/solution/1100-1199/1184.Distance Between Bus Stops/README_EN.md index d947861120f5a..b4e5e94f2f0f6 100644 --- a/solution/1100-1199/1184.Distance Between Bus Stops/README_EN.md +++ b/solution/1100-1199/1184.Distance Between Bus Stops/README_EN.md @@ -25,13 +25,17 @@ tags:

Return the shortest distance between the given start and destination stops.

 

+

Example 1:

+
 Input: distance = [1,2,3,4], start = 0, destination = 1
+
 Output: 1
+
 Explanation: Distance between 0 and 1 is 1 or 9, minimum is 1.

 

@@ -41,9 +45,13 @@ tags: 

+
 Input: distance = [1,2,3,4], start = 0, destination = 2
+
 Output: 3
+
 Explanation: Distance between 0 and 2 is 3 or 7, minimum is 3.
+

 

@@ -53,19 +61,29 @@ tags: 

+
 Input: distance = [1,2,3,4], start = 0, destination = 3
+
 Output: 4
+
 Explanation: Distance between 0 and 3 is 6 or 4, minimum is 4.
+

 

+

Constraints:

diff --git a/solution/1200-1299/1238.Circular Permutation in Binary Representation/README_EN.md b/solution/1200-1299/1238.Circular Permutation in Binary Representation/README_EN.md index 57a0b48ed9325..f3d3a209aa212 100644 --- a/solution/1200-1299/1238.Circular Permutation in Binary Representation/README_EN.md +++ b/solution/1200-1299/1238.Circular Permutation in Binary Representation/README_EN.md @@ -23,35 +23,53 @@ tags:

Given 2 integers n and start. Your task is return any permutation p of (0,1,2.....,2^n -1) such that :

 

+

Example 1:

+
 Input: n = 2, start = 3
+
 Output: [3,2,0,1]
+
 Explanation: The binary representation of the permutation is (11,10,00,01). 
+
 All the adjacent element differ by one bit. Another valid permutation is [3,1,0,2]
+

Example 2:

+
 Input: n = 3, start = 2
+
 Output: [2,6,7,5,4,0,1,3]
+
 Explanation: The binary representation of the permutation is (010,110,111,101,100,000,001,011).
+

 

+

Constraints:

diff --git a/solution/1200-1299/1256.Encode Number/README_EN.md b/solution/1200-1299/1256.Encode Number/README_EN.md index 8793661958481..43b8d3ed61ded 100644 --- a/solution/1200-1299/1256.Encode Number/README_EN.md +++ b/solution/1200-1299/1256.Encode Number/README_EN.md @@ -27,25 +27,35 @@ tags:

 

+

Example 1:

+
 Input: num = 23
+
 Output: "1000"
+

Example 2:

+
 Input: num = 107
+
 Output: "101100"
+

 

+

Constraints:

diff --git a/solution/1300-1399/1301.Number of Paths with Max Score/README_EN.md b/solution/1300-1399/1301.Number of Paths with Max Score/README_EN.md index e9ae14167981a..42f8aab8492d8 100644 --- a/solution/1300-1399/1301.Number of Paths with Max Score/README_EN.md +++ b/solution/1300-1399/1301.Number of Paths with Max Score/README_EN.md @@ -29,21 +29,35 @@ tags:

In case there is no path, return [0, 0].

 

+

Example 1:

+ 
Input: board = ["E23","2X2","12S"]
+
 Output: [7,1]
+

Example 2:

+ 
Input: board = ["E12","1X1","21S"]
+
 Output: [4,2]
+

Example 3:

+ 
Input: board = ["E11","XXX","11S"]
+
 Output: [0,0]
+
+

 

+

Constraints:

diff --git a/solution/1300-1399/1318.Minimum Flips to Make a OR b Equal to c/README_EN.md b/solution/1300-1399/1318.Minimum Flips to Make a OR b Equal to c/README_EN.md index 25cf3e136deec..5d94e91fb76df 100644 --- a/solution/1300-1399/1318.Minimum Flips to Make a OR b Equal to c/README_EN.md +++ b/solution/1300-1399/1318.Minimum Flips to Make a OR b Equal to c/README_EN.md @@ -19,39 +19,55 @@ tags:

Given 3 positives numbers a, b and c. Return the minimum flips required in some bits of a and b to make ( a OR b == c ). (bitwise OR operation).
+ Flip operation consists of change any single bit 1 to 0 or change the bit 0 to 1 in their binary representation.

 

+

Example 1:

+
 Input: a = 2, b = 6, c = 5
+
 Output: 3
+
 Explanation: After flips a = 1 , b = 4 , c = 5 such that (a OR b == c)

Example 2:

+
 Input: a = 4, b = 2, c = 7
+
 Output: 1
+

Example 3:

+
 Input: a = 1, b = 2, c = 3
+
 Output: 0
+

 

+

Constraints:

diff --git a/solution/1300-1399/1324.Print Words Vertically/README_EN.md b/solution/1300-1399/1324.Print Words Vertically/README_EN.md index e1542d061c72f..c86ec25b2c2cb 100644 --- a/solution/1300-1399/1324.Print Words Vertically/README_EN.md +++ b/solution/1300-1399/1324.Print Words Vertically/README_EN.md @@ -21,46 +21,71 @@ tags:

Given a string s. Return all the words vertically in the same order in which they appear in s.
+ Words are returned as a list of strings, complete with spaces when is necessary. (Trailing spaces are not allowed).
+ Each word would be put on only one column and that in one column there will be only one word.

 

+

Example 1:

+
 Input: s = "HOW ARE YOU"
+
 Output: ["HAY","ORO","WEU"]
+
 Explanation: Each word is printed vertically. 
+
  "HAY"
+
  "ORO"
+
  "WEU"
+

Example 2:

+
 Input: s = "TO BE OR NOT TO BE"
+
 Output: ["TBONTB","OEROOE","   T"]
+
 Explanation: Trailing spaces is not allowed. 
+
 "TBONTB"
+
 "OEROOE"
+
 "   T"
+

Example 3:

+
 Input: s = "CONTEST IS COMING"
+
 Output: ["CIC","OSO","N M","T I","E N","S G","T"]
+

 

+

Constraints:

diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README.md b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README.md index 254a012c014fd..62f952989d70e 100644 --- a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README.md +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README.md @@ -86,6 +86,18 @@ tags: ### 方法一：DFS +我们用一个字符串 $\textit{s}$ 来记录当前的字符串，初始时为空字符串。然后，我们设计一个函数 $\text{dfs}$，用来生成所有长度为 $n$ 的开心字符串。 + +函数 $\text{dfs}$ 的具体实现如下： + +1. 如果当前字符串的长度等于 $n$，则将当前字符串加入答案数组 $\textit{ans}$ 中，然后返回； +2. 如果答案数组的长度大于等于 $k$，则直接返回； +3. 否则，我们遍历字符集 $\{a, b, c\}$，对于每个字符 $c$，如果当前字符串为空，或者当前字符串的最后一个字符不等于 $c$，则将字符 $c$ 加入当前字符串，然后递归调用 $\text{dfs}$，递归结束后，将当前字符串的最后一个字符删除。 + +最后，我们判断答案数组的长度是否小于 $k$，如果是，则返回空字符串，否则返回答案数组的第 $k-1$ 个元素。 + +时间复杂度 $O(n \times 2^n)$，空间复杂度 $O(n)$。其中 $n$ 为字符串长度。 + #### Python3 @@ -93,18 +105,22 @@ tags: ```python class Solution: def getHappyString(self, n: int, k: int) -> str: - def dfs(t): - if len(t) == n: - ans.append(t) + def dfs(): + if len(s) == n: + ans.append("".join(s)) + return + if len(ans) >= k: return - for c in 'abc': - if t and t[-1] == c: - continue - dfs(t + c) + for c in "abc": + if not s or s[-1] != c: + s.append(c) + dfs() + s.pop() ans = [] - dfs('') - return '' if len(ans) < k else ans[k - 1] + s = [] + dfs() + return "" if len(ans) < k else ans[k - 1] ``` #### Java @@ -112,22 +128,30 @@ class Solution: ```java class Solution { private List ans = new ArrayList<>(); + private StringBuilder s = new StringBuilder(); + private int n, k; public String getHappyString(int n, int k) { - dfs("", n); + this.n = n; + this.k = k; + dfs(); return ans.size() < k ? "" : ans.get(k - 1); } - private void dfs(String t, int n) { - if (t.length() == n) { - ans.add(t); + private void dfs() { + if (s.length() == n) { + ans.add(s.toString()); + return; + } + if (ans.size() >= k) { return; } for (char c : "abc".toCharArray()) { - if (t.length() > 0 && t.charAt(t.length() - 1) == c) { - continue; + if (s.isEmpty() || s.charAt(s.length() - 1) != c) { + s.append(c); + dfs(); + s.deleteCharAt(s.length() - 1); } - dfs(t + c, n); } } } @@ -138,25 +162,62 @@ class Solution { ```cpp class Solution { public: - vector ans; string getHappyString(int n, int k) { - dfs("", n); + vector ans; + string s = ""; + auto dfs = [&](this auto&& dfs) -> void { + if (s.size() == n) { + ans.emplace_back(s); + return; + } + if (ans.size() >= k) { + return; + } + for (char c = 'a'; c <= 'c'; ++c) { + if (s.empty() || s.back() != c) { + s.push_back(c); + dfs(); + s.pop_back(); + } + } + }; + dfs(); return ans.size() < k ? "" : ans[k - 1]; } +}; +``` - void dfs(string t, int n) { - if (t.size() == n) { - ans.push_back(t); - return; +#### Go + +```go +func getHappyString(n int, k int) string { + ans := []string{} + var s []byte + + var dfs func() + dfs = func() { + if len(s) == n { + ans = append(ans, string(s)) + return + } + if len(ans) >= k { + return } - for (int c = 'a'; c <= 'c'; ++c) { - if (t.size() && t.back() == c) continue; - t.push_back(c); - dfs(t, n); - t.pop_back(); + for c := byte('a'); c <= 'c'; c++ { + if len(s) == 0 || s[len(s)-1] != c { + s = append(s, c) + dfs() + s = s[:len(s)-1] + } } } -}; + + dfs() + if len(ans) < k { + return "" + } + return ans[k-1] +} ``` #### TypeScript @@ -164,46 +225,124 @@ public: ```ts function getHappyString(n: number, k: number): string { const ans: string[] = []; - - const dfs = (s = '') => { + const s: string[] = []; + const dfs = () => { if (s.length === n) { - ans.push(s); + ans.push(s.join('')); return; } - - for (const ch of 'abc') { - if (s.at(-1) === ch) continue; - dfs(s + ch); + if (ans.length >= k) { + return; + } + for (const c of 'abc') { + if (!s.length || s.at(-1)! !== c) { + s.push(c); + dfs(); + s.pop(); + } } }; - dfs(); - return ans[k - 1] ?? ''; } ``` +#### Rust + +```rust +impl Solution { + pub fn get_happy_string(n: i32, k: i32) -> String { + let mut ans = Vec::new(); + let mut s = String::new(); + let mut k = k; + + fn dfs(n: i32, s: &mut String, ans: &mut Vec, k: &mut i32) { + if s.len() == n as usize { + ans.push(s.clone()); + return; + } + if ans.len() >= *k as usize { + return; + } + for c in "abc".chars() { + if s.is_empty() || s.chars().last() != Some(c) { + s.push(c); + dfs(n, s, ans, k); + s.pop(); + } + } + } + + dfs(n, &mut s, &mut ans, &mut k); + if ans.len() < k as usize { + "".to_string() + } else { + ans[(k - 1) as usize].clone() + } + } +} +``` + #### JavaScript ```js -function getHappyString(n, k) { +/** + * @param {number} n + * @param {number} k + * @return {string} + */ +var getHappyString = function (n, k) { const ans = []; - - const dfs = (s = '') => { + const s = []; + const dfs = () => { if (s.length === n) { - ans.push(s); + ans.push(s.join('')); return; } - - for (const ch of 'abc') { - if (s.at(-1) === ch) continue; - dfs(s + ch); + if (ans.length >= k) { + return; + } + for (const c of 'abc') { + if (!s.length || s.at(-1) !== c) { + s.push(c); + dfs(); + s.pop(); + } } }; - dfs(); - return ans[k - 1] ?? ''; +}; +``` + +#### C# + +```cs +public class Solution { + public string GetHappyString(int n, int k) { + List ans = new List(); + StringBuilder s = new StringBuilder(); + + void Dfs() { + if (s.Length == n) { + ans.Add(s.ToString()); + return; + } + if (ans.Count >= k) { + return; + } + foreach (char c in "abc") { + if (s.Length == 0 || s[s.Length - 1] != c) { + s.Append(c); + Dfs(); + s.Length--; + } + } + } + + Dfs(); + return ans.Count < k ? "" : ans[k - 1]; + } } ``` diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README_EN.md b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README_EN.md index f1c0ddf2c09dd..a1d600e38195f 100644 --- a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README_EN.md +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/README_EN.md @@ -71,7 +71,19 @@ tags: -### Solution 1 +### Solution 1: DFS + +We use a string $\textit{s}$ to record the current string, initially an empty string. Then, we design a function $\text{dfs}$ to generate all happy strings of length $n$. + +The implementation of the function $\text{dfs}$ is as follows: + +1. If the length of the current string is equal to $n$, add the current string to the answer array $\textit{ans}$ and return; +2. If the length of the answer array is greater than or equal to $k$, return directly; +3. Otherwise, we iterate over the character set $\{a, b, c\}$. For each character $c$, if the current string is empty or the last character of the current string is not equal to $c$, add the character $c$ to the current string, then recursively call $\text{dfs}$. After the recursion ends, remove the last character of the current string. + +Finally, we check if the length of the answer array is less than $k$. If it is, return an empty string; otherwise, return the $k$-th element of the answer array. + +The time complexity is $O(n \times 2^n)$, and the space complexity is $O(n)$. Here, $n$ is the length of the string. @@ -80,18 +92,22 @@ tags: ```python class Solution: def getHappyString(self, n: int, k: int) -> str: - def dfs(t): - if len(t) == n: - ans.append(t) + def dfs(): + if len(s) == n: + ans.append("".join(s)) + return + if len(ans) >= k: return - for c in 'abc': - if t and t[-1] == c: - continue - dfs(t + c) + for c in "abc": + if not s or s[-1] != c: + s.append(c) + dfs() + s.pop() ans = [] - dfs('') - return '' if len(ans) < k else ans[k - 1] + s = [] + dfs() + return "" if len(ans) < k else ans[k - 1] ``` #### Java @@ -99,22 +115,30 @@ class Solution: ```java class Solution { private List ans = new ArrayList<>(); + private StringBuilder s = new StringBuilder(); + private int n, k; public String getHappyString(int n, int k) { - dfs("", n); + this.n = n; + this.k = k; + dfs(); return ans.size() < k ? "" : ans.get(k - 1); } - private void dfs(String t, int n) { - if (t.length() == n) { - ans.add(t); + private void dfs() { + if (s.length() == n) { + ans.add(s.toString()); + return; + } + if (ans.size() >= k) { return; } for (char c : "abc".toCharArray()) { - if (t.length() > 0 && t.charAt(t.length() - 1) == c) { - continue; + if (s.isEmpty() || s.charAt(s.length() - 1) != c) { + s.append(c); + dfs(); + s.deleteCharAt(s.length() - 1); } - dfs(t + c, n); } } } @@ -125,25 +149,62 @@ class Solution { ```cpp class Solution { public: - vector ans; string getHappyString(int n, int k) { - dfs("", n); + vector ans; + string s = ""; + auto dfs = [&](this auto&& dfs) -> void { + if (s.size() == n) { + ans.emplace_back(s); + return; + } + if (ans.size() >= k) { + return; + } + for (char c = 'a'; c <= 'c'; ++c) { + if (s.empty() || s.back() != c) { + s.push_back(c); + dfs(); + s.pop_back(); + } + } + }; + dfs(); return ans.size() < k ? "" : ans[k - 1]; } +}; +``` - void dfs(string t, int n) { - if (t.size() == n) { - ans.push_back(t); - return; +#### Go + +```go +func getHappyString(n int, k int) string { + ans := []string{} + var s []byte + + var dfs func() + dfs = func() { + if len(s) == n { + ans = append(ans, string(s)) + return + } + if len(ans) >= k { + return } - for (int c = 'a'; c <= 'c'; ++c) { - if (t.size() && t.back() == c) continue; - t.push_back(c); - dfs(t, n); - t.pop_back(); + for c := byte('a'); c <= 'c'; c++ { + if len(s) == 0 || s[len(s)-1] != c { + s = append(s, c) + dfs() + s = s[:len(s)-1] + } } } -}; + + dfs() + if len(ans) < k { + return "" + } + return ans[k-1] +} ``` #### TypeScript @@ -151,46 +212,124 @@ public: ```ts function getHappyString(n: number, k: number): string { const ans: string[] = []; - - const dfs = (s = '') => { + const s: string[] = []; + const dfs = () => { if (s.length === n) { - ans.push(s); + ans.push(s.join('')); return; } - - for (const ch of 'abc') { - if (s.at(-1) === ch) continue; - dfs(s + ch); + if (ans.length >= k) { + return; + } + for (const c of 'abc') { + if (!s.length || s.at(-1)! !== c) { + s.push(c); + dfs(); + s.pop(); + } } }; - dfs(); - return ans[k - 1] ?? ''; } ``` +#### Rust + +```rust +impl Solution { + pub fn get_happy_string(n: i32, k: i32) -> String { + let mut ans = Vec::new(); + let mut s = String::new(); + let mut k = k; + + fn dfs(n: i32, s: &mut String, ans: &mut Vec, k: &mut i32) { + if s.len() == n as usize { + ans.push(s.clone()); + return; + } + if ans.len() >= *k as usize { + return; + } + for c in "abc".chars() { + if s.is_empty() || s.chars().last() != Some(c) { + s.push(c); + dfs(n, s, ans, k); + s.pop(); + } + } + } + + dfs(n, &mut s, &mut ans, &mut k); + if ans.len() < k as usize { + "".to_string() + } else { + ans[(k - 1) as usize].clone() + } + } +} +``` + #### JavaScript ```js -function getHappyString(n, k) { +/** + * @param {number} n + * @param {number} k + * @return {string} + */ +var getHappyString = function (n, k) { const ans = []; - - const dfs = (s = '') => { + const s = []; + const dfs = () => { if (s.length === n) { - ans.push(s); + ans.push(s.join('')); return; } - - for (const ch of 'abc') { - if (s.at(-1) === ch) continue; - dfs(s + ch); + if (ans.length >= k) { + return; + } + for (const c of 'abc') { + if (!s.length || s.at(-1) !== c) { + s.push(c); + dfs(); + s.pop(); + } } }; - dfs(); - return ans[k - 1] ?? ''; +}; +``` + +#### C# + +```cs +public class Solution { + public string GetHappyString(int n, int k) { + List ans = new List(); + StringBuilder s = new StringBuilder(); + + void Dfs() { + if (s.Length == n) { + ans.Add(s.ToString()); + return; + } + if (ans.Count >= k) { + return; + } + foreach (char c in "abc") { + if (s.Length == 0 || s[s.Length - 1] != c) { + s.Append(c); + Dfs(); + s.Length--; + } + } + } + + Dfs(); + return ans.Count < k ? "" : ans[k - 1]; + } } ``` diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cpp b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cpp index 33c13dad5b07a..83d3016fc02ad 100644 --- a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cpp +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cpp @@ -1,21 +1,25 @@ class Solution { public: - vector ans; string getHappyString(int n, int k) { - dfs("", n); + vector ans; + string s = ""; + auto dfs = [&](this auto&& dfs) -> void { + if (s.size() == n) { + ans.emplace_back(s); + return; + } + if (ans.size() >= k) { + return; + } + for (char c = 'a'; c <= 'c'; ++c) { + if (s.empty() || s.back() != c) { + s.push_back(c); + dfs(); + s.pop_back(); + } + } + }; + dfs(); return ans.size() < k ? "" : ans[k - 1]; } - - void dfs(string t, int n) { - if (t.size() == n) { - ans.push_back(t); - return; - } - for (int c = 'a'; c <= 'c'; ++c) { - if (t.size() && t.back() == c) continue; - t.push_back(c); - dfs(t, n); - t.pop_back(); - } - } -}; \ No newline at end of file +}; diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cs b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cs new file mode 100644 index 0000000000000..7f9c275f536ac --- /dev/null +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.cs @@ -0,0 +1,26 @@ +public class Solution { + public string GetHappyString(int n, int k) { + List ans = new List(); + StringBuilder s = new StringBuilder(); + + void Dfs() { + if (s.Length == n) { + ans.Add(s.ToString()); + return; + } + if (ans.Count >= k) { + return; + } + foreach (char c in "abc") { + if (s.Length == 0 || s[s.Length - 1] != c) { + s.Append(c); + Dfs(); + s.Length--; + } + } + } + + Dfs(); + return ans.Count < k ? "" : ans[k - 1]; + } +} diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.go b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.go new file mode 100644 index 0000000000000..42fe5cf0cbe94 --- /dev/null +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.go @@ -0,0 +1,28 @@ +func getHappyString(n int, k int) string { + ans := []string{} + var s []byte + + var dfs func() + dfs = func() { + if len(s) == n { + ans = append(ans, string(s)) + return + } + if len(ans) >= k { + return + } + for c := byte('a'); c <= 'c'; c++ { + if len(s) == 0 || s[len(s)-1] != c { + s = append(s, c) + dfs() + s = s[:len(s)-1] + } + } + } + + dfs() + if len(ans) < k { + return "" + } + return ans[k-1] +} diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.java b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.java index a9a86e3b6a8c0..5eca4c6418dd0 100644 --- a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.java +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.java @@ -1,21 +1,29 @@ class Solution { private List ans = new ArrayList<>(); + private StringBuilder s = new StringBuilder(); + private int n, k; public String getHappyString(int n, int k) { - dfs("", n); + this.n = n; + this.k = k; + dfs(); return ans.size() < k ? "" : ans.get(k - 1); } - private void dfs(String t, int n) { - if (t.length() == n) { - ans.add(t); + private void dfs() { + if (s.length() == n) { + ans.add(s.toString()); + return; + } + if (ans.size() >= k) { return; } for (char c : "abc".toCharArray()) { - if (t.length() > 0 && t.charAt(t.length() - 1) == c) { - continue; + if (s.isEmpty() || s.charAt(s.length() - 1) != c) { + s.append(c); + dfs(); + s.deleteCharAt(s.length() - 1); } - dfs(t + c, n); } } -} \ No newline at end of file +} diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.js b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.js index e349343e318ff..35e45207500c4 100644 --- a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.js +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.js @@ -1,19 +1,27 @@ -function getHappyString(n, k) { +/** + * @param {number} n + * @param {number} k + * @return {string} + */ +var getHappyString = function (n, k) { const ans = []; - - const dfs = (s = '') => { + const s = []; + const dfs = () => { if (s.length === n) { - ans.push(s); + ans.push(s.join('')); return; } - - for (const ch of 'abc') { - if (s.at(-1) === ch) continue; - dfs(s + ch); + if (ans.length >= k) { + return; + } + for (const c of 'abc') { + if (!s.length || s.at(-1) !== c) { + s.push(c); + dfs(); + s.pop(); + } } }; - dfs(); - return ans[k - 1] ?? ''; -} +}; diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.py b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.py index d394dc49dfa5d..7efc3ad4f1f41 100644 --- a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.py +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.py @@ -1,14 +1,18 @@ class Solution: def getHappyString(self, n: int, k: int) -> str: - def dfs(t): - if len(t) == n: - ans.append(t) + def dfs(): + if len(s) == n: + ans.append("".join(s)) return - for c in 'abc': - if t and t[-1] == c: - continue - dfs(t + c) + if len(ans) >= k: + return + for c in "abc": + if not s or s[-1] != c: + s.append(c) + dfs() + s.pop() ans = [] - dfs('') - return '' if len(ans) < k else ans[k - 1] + s = [] + dfs() + return "" if len(ans) < k else ans[k - 1] diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.rs b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.rs new file mode 100644 index 0000000000000..95354a544d4ee --- /dev/null +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.rs @@ -0,0 +1,31 @@ +impl Solution { + pub fn get_happy_string(n: i32, k: i32) -> String { + let mut ans = Vec::new(); + let mut s = String::new(); + let mut k = k; + + fn dfs(n: i32, s: &mut String, ans: &mut Vec, k: &mut i32) { + if s.len() == n as usize { + ans.push(s.clone()); + return; + } + if ans.len() >= *k as usize { + return; + } + for c in "abc".chars() { + if s.is_empty() || s.chars().last() != Some(c) { + s.push(c); + dfs(n, s, ans, k); + s.pop(); + } + } + } + + dfs(n, &mut s, &mut ans, &mut k); + if ans.len() < k as usize { + "".to_string() + } else { + ans[(k - 1) as usize].clone() + } + } +} diff --git a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.ts b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.ts index 8f421ccaf92f4..b676a2f42b60a 100644 --- a/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.ts +++ b/solution/1400-1499/1415.The k-th Lexicographical String of All Happy Strings of Length n/Solution.ts @@ -1,19 +1,22 @@ function getHappyString(n: number, k: number): string { const ans: string[] = []; - - const dfs = (s = '') => { + const s: string[] = []; + const dfs = () => { if (s.length === n) { - ans.push(s); + ans.push(s.join('')); return; } - - for (const ch of 'abc') { - if (s.at(-1) === ch) continue; - dfs(s + ch); + if (ans.length >= k) { + return; + } + for (const c of 'abc') { + if (!s.length || s.at(-1)! !== c) { + s.push(c); + dfs(); + s.pop(); + } } }; - dfs(); - return ans[k - 1] ?? ''; } diff --git a/solution/1400-1499/1418.Display Table of Food Orders in a Restaurant/README_EN.md b/solution/1400-1499/1418.Display Table of Food Orders in a Restaurant/README_EN.md index 809ec164c6da3..dd6bc86d1a53a 100644 --- a/solution/1400-1499/1418.Display Table of Food Orders in a Restaurant/README_EN.md +++ b/solution/1400-1499/1418.Display Table of Food Orders in a Restaurant/README_EN.md @@ -27,48 +27,77 @@ tags:

Return the restaurant's “display table”. The “display table” is a table whose row entries denote how many of each food item each table ordered. The first column is the table number and the remaining columns correspond to each food item in alphabetical order. The first row should be a header whose first column is “Table”, followed by the names of the food items. Note that the customer names are not part of the table. Additionally, the rows should be sorted in numerically increasing order.

 

+

Example 1:

+
 Input: orders = [["David","3","Ceviche"],["Corina","10","Beef Burrito"],["David","3","Fried Chicken"],["Carla","5","Water"],["Carla","5","Ceviche"],["Rous","3","Ceviche"]]
+
 Output: [["Table","Beef Burrito","Ceviche","Fried Chicken","Water"],["3","0","2","1","0"],["5","0","1","0","1"],["10","1","0","0","0"]] 
+
 Explanation:
+
 The displaying table looks like:
+
 Table,Beef Burrito,Ceviche,Fried Chicken,Water
+
 3    ,0           ,2      ,1            ,0
+
 5    ,0           ,1      ,0            ,1
+
 10   ,1           ,0      ,0            ,0
+
 For the table 3: David orders "Ceviche" and "Fried Chicken", and Rous orders "Ceviche".
+
 For the table 5: Carla orders "Water" and "Ceviche".
+
 For the table 10: Corina orders "Beef Burrito". 
+

Example 2:

+
 Input: orders = [["James","12","Fried Chicken"],["Ratesh","12","Fried Chicken"],["Amadeus","12","Fried Chicken"],["Adam","1","Canadian Waffles"],["Brianna","1","Canadian Waffles"]]
+
 Output: [["Table","Canadian Waffles","Fried Chicken"],["1","2","0"],["12","0","3"]] 
+
 Explanation: 
+
 For the table 1: Adam and Brianna order "Canadian Waffles".
+
 For the table 12: James, Ratesh and Amadeus order "Fried Chicken".
+

Example 3:

+
 Input: orders = [["Laura","2","Bean Burrito"],["Jhon","2","Beef Burrito"],["Melissa","2","Soda"]]
+
 Output: [["Table","Bean Burrito","Beef Burrito","Soda"],["2","1","1","1"]]
+

 

+

Constraints:

    -
  • 1 <= orders.length <= 5 * 10^4
    • -
  • orders[i].length == 3
    • -
  • 1 <= customerNamei.length, foodItemi.length <= 20
    • -
  • customerNamei and foodItemi consist of lowercase and uppercase English letters and the space character.
    • -
  • tableNumberi is a valid integer between 1 and 500.
    • + +
  • 1 <= orders.length <= 5 * 10^4
    • + +
  • orders[i].length == 3
    • + +
  • 1 <= customerNamei.length, foodItemi.length <= 20
    • + +
  • customerNamei and foodItemi consist of lowercase and uppercase English letters and the space character.
    • + +
  • tableNumberi is a valid integer between 1 and 500.
    • +
diff --git a/solution/1400-1499/1448.Count Good Nodes in Binary Tree/README_EN.md b/solution/1400-1499/1448.Count Good Nodes in Binary Tree/README_EN.md index 75f9d52c74990..4a07c72b0b946 100644 --- a/solution/1400-1499/1448.Count Good Nodes in Binary Tree/README_EN.md +++ b/solution/1400-1499/1448.Count Good Nodes in Binary Tree/README_EN.md @@ -26,17 +26,25 @@ tags:

Return the number of good nodes in the binary tree.

 

+

Example 1:

+
 Input: root = [3,1,4,3,null,1,5]
+
 Output: 4
+
 Explanation: Nodes in blue are good.
+
 Root Node (3) is always a good node.
+
 Node 4 -> (3,4) is the maximum value in the path starting from the root.
+
 Node 5 -> (3,4,5) is the maximum value in the path
+
 Node 3 -> (3,1,3) is the maximum value in the path.

Example 2:

@@ -44,23 +52,33 @@ Node 3 -> (3,1,3) is the maximum value in the path. 

+
 Input: root = [3,3,null,4,2]
+
 Output: 3
+
 Explanation: Node 2 -> (3, 3, 2) is not good, because "3" is higher than it.

Example 3:

+
 Input: root = [1]
+
 Output: 1
+
 Explanation: Root is considered as good.

 

+

Constraints:

    -
  • The number of nodes in the binary tree is in the range [1, 10^5].
    • -
  • Each node's value is between [-10^4, 10^4].
    • + +
  • The number of nodes in the binary tree is in the range [1, 10^5].
    • + +
  • Each node's value is between [-10^4, 10^4].
    • +
diff --git a/solution/1400-1499/1470.Shuffle the Array/README_EN.md b/solution/1400-1499/1470.Shuffle the Array/README_EN.md index 9246c35a92d80..8a806cd3fd73d 100644 --- a/solution/1400-1499/1470.Shuffle the Array/README_EN.md +++ b/solution/1400-1499/1470.Shuffle the Array/README_EN.md @@ -23,35 +23,51 @@ tags:

Return the array in the form [x1,y1,x2,y2,...,xn,yn].

 

+

Example 1:

+
 Input: nums = [2,5,1,3,4,7], n = 3
+
 Output: [2,3,5,4,1,7] 
+
 Explanation: Since x1=2, x2=5, x3=1, y1=3, y2=4, y3=7 then the answer is [2,3,5,4,1,7].
+

Example 2:

+
 Input: nums = [1,2,3,4,4,3,2,1], n = 4
+
 Output: [1,4,2,3,3,2,4,1]
+

Example 3:

+
 Input: nums = [1,1,2,2], n = 2
+
 Output: [1,2,1,2]
+

 

+

Constraints:

    -
  • 1 <= n <= 500
    • -
  • nums.length == 2n
    • -
  • 1 <= nums[i] <= 10^3
    • + +
  • 1 <= n <= 500
    • + +
  • nums.length == 2n
    • + +
  • 1 <= nums[i] <= 10^3
    • +
diff --git a/solution/1400-1499/1481.Least Number of Unique Integers after K Removals/README_EN.md b/solution/1400-1499/1481.Least Number of Unique Integers after K Removals/README_EN.md index 00dee15fada33..d367cf0458c18 100644 --- a/solution/1400-1499/1481.Least Number of Unique Integers after K Removals/README_EN.md +++ b/solution/1400-1499/1481.Least Number of Unique Integers after K Removals/README_EN.md @@ -25,31 +25,45 @@ tags:

Given an array of integers arr and an integer k. Find the least number of unique integers after removing exactly k elements.

    +

 

+

Example 1:

+
 Input: arr = [5,5,4], k = 1
+
 Output: 1
+
 Explanation: Remove the single 4, only 5 is left.
+
Example 2: 
+
 Input: arr = [4,3,1,1,3,3,2], k = 3
+
 Output: 2
+
 Explanation: Remove 4, 2 and either one of the two 1s or three 3s. 1 and 3 will be left.

 

+

Constraints:

    -
  • 1 <= arr.length <= 10^5
    • -
  • 1 <= arr[i] <= 10^9
    • -
  • 0 <= k <= arr.length
    • + +
  • 1 <= arr.length <= 10^5
    • + +
  • 1 <= arr[i] <= 10^9
    • + +
  • 0 <= k <= arr.length
    • +
diff --git a/solution/1500-1599/1523.Count Odd Numbers in an Interval Range/README_EN.md b/solution/1500-1599/1523.Count Odd Numbers in an Interval Range/README_EN.md index d1eea923bf055..03cb439cf8dbc 100644 --- a/solution/1500-1599/1523.Count Odd Numbers in an Interval Range/README_EN.md +++ b/solution/1500-1599/1523.Count Odd Numbers in an Interval Range/README_EN.md @@ -21,25 +21,35 @@ tags:

Given two non-negative integers low and high. Return the count of odd numbers between low and high (inclusive).

 

+

Example 1:

+
 Input: low = 3, high = 7
+
 Output: 3
+
 Explanation: The odd numbers between 3 and 7 are [3,5,7].

Example 2:

+
 Input: low = 8, high = 10
+
 Output: 1
+
 Explanation: The odd numbers between 8 and 10 are [9].

 

+

Constraints:

    -
  • 0 <= low <= high <= 10^9
    • + +
  • 0 <= low <= high <= 10^9
    • +
diff --git a/solution/1500-1599/1534.Count Good Triplets/README_EN.md b/solution/1500-1599/1534.Count Good Triplets/README_EN.md index cdec96dfb8cd3..1a417e60574bf 100644 --- a/solution/1500-1599/1534.Count Good Triplets/README_EN.md +++ b/solution/1500-1599/1534.Count Good Triplets/README_EN.md @@ -24,10 +24,15 @@ tags:

A triplet (arr[i], arr[j], arr[k]) is good if the following conditions are true:

    -
  • 0 <= i < j < k < arr.length
    • -
  • |arr[i] - arr[j]| <= a
    • -
  • |arr[j] - arr[k]| <= b
    • -
  • |arr[i] - arr[k]| <= c
    • + +
  • 0 <= i < j < k < arr.length
    • + +
  • |arr[i] - arr[j]| <= a
    • + +
  • |arr[j] - arr[k]| <= b
    • + +
  • |arr[i] - arr[k]| <= c
    • +

Where |x| denotes the absolute value of x.

@@ -35,29 +40,43 @@ tags:

Return the number of good triplets.

 

+

Example 1:

+
 Input: arr = [3,0,1,1,9,7], a = 7, b = 2, c = 3
+
 Output: 4
+
 Explanation: There are 4 good triplets: [(3,0,1), (3,0,1), (3,1,1), (0,1,1)].
+

Example 2:

+
 Input: arr = [1,1,2,2,3], a = 0, b = 0, c = 1
+
 Output: 0
+
 Explanation: No triplet satisfies all conditions.
+

 

+

Constraints:

    -
  • 3 <= arr.length <= 100
    • -
  • 0 <= arr[i] <= 1000
    • -
  • 0 <= a, b, c <= 1000
    • + +
  • 3 <= arr.length <= 100
    • + +
  • 0 <= arr[i] <= 1000
    • + +
  • 0 <= a, b, c <= 1000
    • +
diff --git a/solution/1600-1699/1617.Count Subtrees With Max Distance Between Cities/README_EN.md b/solution/1600-1699/1617.Count Subtrees With Max Distance Between Cities/README_EN.md index 58a5aa233655e..a39d7dd0a4861 100644 --- a/solution/1600-1699/1617.Count Subtrees With Max Distance Between Cities/README_EN.md +++ b/solution/1600-1699/1617.Count Subtrees With Max Distance Between Cities/README_EN.md @@ -33,42 +33,63 @@ tags:

Notice that the distance between the two cities is the number of edges in the path between them.

 

+

Example 1:

+
 Input: n = 4, edges = [[1,2],[2,3],[2,4]]
+
 Output: [3,4,0]
+
 Explanation:
+
 The subtrees with subsets {1,2}, {2,3} and {2,4} have a max distance of 1.
+
 The subtrees with subsets {1,2,3}, {1,2,4}, {2,3,4} and {1,2,3,4} have a max distance of 2.
+
 No subtree has two nodes where the max distance between them is 3.
+

Example 2:

+
 Input: n = 2, edges = [[1,2]]
+
 Output: [1]
+

Example 3:

+
 Input: n = 3, edges = [[1,2],[2,3]]
+
 Output: [2,1]
+

 

+

Constraints:

    -
  • 2 <= n <= 15
    • -
  • edges.length == n-1
    • -
  • edges[i].length == 2
    • -
  • 1 <= ui, vi <= n
    • -
  • All pairs (ui, vi) are distinct.
    • + +
  • 2 <= n <= 15
    • + +
  • edges.length == n-1
    • + +
  • edges[i].length == 2
    • + +
  • 1 <= ui, vi <= n
    • + +
  • All pairs (ui, vi) are distinct.
    • +
diff --git a/solution/1600-1699/1618.Maximum Font to Fit a Sentence in a Screen/README_EN.md b/solution/1600-1699/1618.Maximum Font to Fit a Sentence in a Screen/README_EN.md index 637b3531cdded..86b831b8cd79f 100644 --- a/solution/1600-1699/1618.Maximum Font to Fit a Sentence in a Screen/README_EN.md +++ b/solution/1600-1699/1618.Maximum Font to Fit a Sentence in a Screen/README_EN.md @@ -26,14 +26,23 @@ tags:

The FontInfo interface is defined as such:

+
 interface FontInfo {
+
   // Returns the width of character ch on the screen using font size fontSize.
+
   // O(1) per call
+
   public int getWidth(int fontSize, char ch);
 
+
+
   // Returns the height of any character on the screen using font size fontSize.
+
   // O(1) per call
+
   public int getHeight(int fontSize);
+
 }

The calculated width of text for some fontSize is the sum of every getWidth(fontSize, text[i]) call for each 0 <= i < text.length (0-indexed). The calculated height of text for some fontSize is getHeight(fontSize). Note that text is displayed on a single line.

@@ -43,45 +52,67 @@ interface FontInfo {

It is also guaranteed that for any font size fontSize and any character ch:

    -
  • getHeight(fontSize) <= getHeight(fontSize+1)
    • -
  • getWidth(fontSize, ch) <= getWidth(fontSize+1, ch)
    • + +
  • getHeight(fontSize) <= getHeight(fontSize+1)
    • + +
  • getWidth(fontSize, ch) <= getWidth(fontSize+1, ch)
    • +

Return the maximum font size you can use to display text on the screen. If text cannot fit on the display with any font size, return -1.

 

+

Example 1:

+
 Input: text = "helloworld", w = 80, h = 20, fonts = [6,8,10,12,14,16,18,24,36]
+
 Output: 6
+

Example 2:

+
 Input: text = "leetcode", w = 1000, h = 50, fonts = [1,2,4]
+
 Output: 4
+

Example 3:

+
 Input: text = "easyquestion", w = 100, h = 100, fonts = [10,15,20,25]
+
 Output: -1
+

 

+

Constraints:

    -
  • 1 <= text.length <= 50000
    • -
  • text contains only lowercase English letters.
    • -
  • 1 <= w <= 107
    • -
  • 1 <= h <= 104
    • -
  • 1 <= fonts.length <= 105
    • -
  • 1 <= fonts[i] <= 105
    • -
  • fonts is sorted in ascending order and does not contain duplicates.
    • + +
  • 1 <= text.length <= 50000
    • + +
  • text contains only lowercase English letters.
    • + +
  • 1 <= w <= 107
    • + +
  • 1 <= h <= 104
    • + +
  • 1 <= fonts.length <= 105
    • + +
  • 1 <= fonts[i] <= 105
    • + +
  • fonts is sorted in ascending order and does not contain duplicates.
    • +
diff --git a/solution/1600-1699/1634.Add Two Polynomials Represented as Linked Lists/README_EN.md b/solution/1600-1699/1634.Add Two Polynomials Represented as Linked Lists/README_EN.md index b5a4c41d13436..107929af544fa 100644 --- a/solution/1600-1699/1634.Add Two Polynomials Represented as Linked Lists/README_EN.md +++ b/solution/1600-1699/1634.Add Two Polynomials Represented as Linked Lists/README_EN.md @@ -23,9 +23,13 @@ tags:

Each node has three attributes:

    -
  • coefficient: an integer representing the number multiplier of the term. The coefficient of the term 9x4 is 9.
    • -
  • power: an integer representing the exponent. The power of the term 9x4 is 4.
    • -
  • next: a pointer to the next node in the list, or null if it is the last node of the list.
    • + +
  • coefficient: an integer representing the number multiplier of the term. The coefficient of the term 9x4 is 9.
    • + +
  • power: an integer representing the exponent. The power of the term 9x4 is 4.
    • + +
  • next: a pointer to the next node in the list, or null if it is the last node of the list.
    • +

For example, the polynomial 5x3 + 4x - 7 is represented by the polynomial linked list illustrated below:

@@ -41,41 +45,61 @@ tags:

The input/output format is as a list of n nodes, where each node is represented as its [coefficient, power]. For example, the polynomial 5x3 + 4x - 7 would be represented as: [[5,3],[4,1],[-7,0]].

 

+

Example 1:

+
 Input: poly1 = [[1,1]], poly2 = [[1,0]]
+
 Output: [[1,1],[1,0]]
+
 Explanation: poly1 = x. poly2 = 1. The sum is x + 1.
+

Example 2:

+
 Input: poly1 = [[2,2],[4,1],[3,0]], poly2 = [[3,2],[-4,1],[-1,0]]
+
 Output: [[5,2],[2,0]]
+
 Explanation: poly1 = 2x2 + 4x + 3. poly2 = 3x2 - 4x - 1. The sum is 5x2 + 2. Notice that we omit the "0x" term.
+

Example 3:

+
 Input: poly1 = [[1,2]], poly2 = [[-1,2]]
+
 Output: []
+
 Explanation: The sum is 0. We return an empty list.
+

 

+

Constraints:

    -
  • 0 <= n <= 104
    • -
  • -109 <= PolyNode.coefficient <= 109
    • -
  • PolyNode.coefficient != 0
    • -
  • 0 <= PolyNode.power <= 109
    • -
  • PolyNode.power > PolyNode.next.power
    • + +
  • 0 <= n <= 104
    • + +
  • -109 <= PolyNode.coefficient <= 109
    • + +
  • PolyNode.coefficient != 0
    • + +
  • 0 <= PolyNode.power <= 109
    • + +
  • PolyNode.power > PolyNode.next.power
    • +
diff --git a/solution/1600-1699/1649.Create Sorted Array through Instructions/README_EN.md b/solution/1600-1699/1649.Create Sorted Array through Instructions/README_EN.md index 429cfe2142d4e..d7708d65d82ee 100644 --- a/solution/1600-1699/1649.Create Sorted Array through Instructions/README_EN.md +++ b/solution/1600-1699/1649.Create Sorted Array through Instructions/README_EN.md @@ -27,8 +27,11 @@ tags:

Given an integer array instructions, you are asked to create a sorted array from the elements in instructions. You start with an empty container nums. For each element from left to right in instructions, insert it into nums. The cost of each insertion is the minimum of the following:

    -
  • The number of elements currently in nums that are strictly less than instructions[i].
    • -
  • The number of elements currently in nums that are strictly greater than instructions[i].
    • + +
  • The number of elements currently in nums that are strictly less than instructions[i].
    • + +
  • The number of elements currently in nums that are strictly greater than instructions[i].
    • +

For example, if inserting element 3 into nums = [1,2,3,5], the cost of insertion is min(2, 1) (elements 1 and 2 are less than 3, element 5 is greater than 3) and nums will become [1,2,3,3,5].

@@ -36,57 +39,95 @@ tags:

Return the total cost to insert all elements from instructions into nums. Since the answer may be large, return it modulo 109 + 7

 

+

Example 1:

+
 Input: instructions = [1,5,6,2]
+
 Output: 1
+
 Explanation: Begin with nums = [].
+
 Insert 1 with cost min(0, 0) = 0, now nums = [1].
+
 Insert 5 with cost min(1, 0) = 0, now nums = [1,5].
+
 Insert 6 with cost min(2, 0) = 0, now nums = [1,5,6].
+
 Insert 2 with cost min(1, 2) = 1, now nums = [1,2,5,6].
+
 The total cost is 0 + 0 + 0 + 1 = 1.

Example 2:

+
 Input: instructions = [1,2,3,6,5,4]
+
 Output: 3
+
 Explanation: Begin with nums = [].
+
 Insert 1 with cost min(0, 0) = 0, now nums = [1].
+
 Insert 2 with cost min(1, 0) = 0, now nums = [1,2].
+
 Insert 3 with cost min(2, 0) = 0, now nums = [1,2,3].
+
 Insert 6 with cost min(3, 0) = 0, now nums = [1,2,3,6].
+
 Insert 5 with cost min(3, 1) = 1, now nums = [1,2,3,5,6].
+
 Insert 4 with cost min(3, 2) = 2, now nums = [1,2,3,4,5,6].
+
 The total cost is 0 + 0 + 0 + 0 + 1 + 2 = 3.
+

Example 3:

+
 Input: instructions = [1,3,3,3,2,4,2,1,2]
+
 Output: 4
+
 Explanation: Begin with nums = [].
+
 Insert 1 with cost min(0, 0) = 0, now nums = [1].
+
 Insert 3 with cost min(1, 0) = 0, now nums = [1,3].
+
 Insert 3 with cost min(1, 0) = 0, now nums = [1,3,3].
+
 Insert 3 with cost min(1, 0) = 0, now nums = [1,3,3,3].
+
 Insert 2 with cost min(1, 3) = 1, now nums = [1,2,3,3,3].
+
 Insert 4 with cost min(5, 0) = 0, now nums = [1,2,3,3,3,4].
+
 ​​​​​​​Insert 2 with cost min(1, 4) = 1, now nums = [1,2,2,3,3,3,4].
+
 ​​​​​​​Insert 1 with cost min(0, 6) = 0, now nums = [1,1,2,2,3,3,3,4].
+
 ​​​​​​​Insert 2 with cost min(2, 4) = 2, now nums = [1,1,2,2,2,3,3,3,4].
+
 The total cost is 0 + 0 + 0 + 0 + 1 + 0 + 1 + 0 + 2 = 4.
+

 

+

Constraints:

    -
  • 1 <= instructions.length <= 105
    • -
  • 1 <= instructions[i] <= 105
    • + +
  • 1 <= instructions.length <= 105
    • + +
  • 1 <= instructions[i] <= 105
    • +
diff --git a/solution/1600-1699/1660.Correct a Binary Tree/README_EN.md b/solution/1600-1699/1660.Correct a Binary Tree/README_EN.md index 4a5e058ed554d..4c4926392dd0d 100644 --- a/solution/1600-1699/1660.Correct a Binary Tree/README_EN.md +++ b/solution/1600-1699/1660.Correct a Binary Tree/README_EN.md @@ -29,22 +29,31 @@ tags:

The test input is read as 3 lines:

    -
  • TreeNode root
    • -
  • int fromNode (not available to correctBinaryTree)
    • -
  • int toNode (not available to correctBinaryTree)
    • + +
  • TreeNode root
    • + +
  • int fromNode (not available to correctBinaryTree)
    • + +
  • int toNode (not available to correctBinaryTree)
    • +

After the binary tree rooted at root is parsed, the TreeNode with value of fromNode will have its right child pointer pointing to the TreeNode with a value of toNode. Then, root is passed to correctBinaryTree.

 

+

Example 1:

+
 Input: root = [1,2,3], fromNode = 2, toNode = 3
+
 Output: [1,null,3]
+
 Explanation: The node with value 2 is invalid, so remove it.
+

Example 2:

@@ -52,22 +61,35 @@ tags: 

+
 Input: root = [8,3,1,7,null,9,4,2,null,null,null,5,6], fromNode = 7, toNode = 4
+
 Output: [8,3,1,null,null,9,4,null,null,5,6]
+
 Explanation: The node with value 7 is invalid, so remove it and the node underneath it, node 2.
+

 

+

Constraints:

    -
  • The number of nodes in the tree is in the range [3, 104].
    • -
  • -109 <= Node.val <= 109
    • -
  • All Node.val are unique.
    • -
  • fromNode != toNode
    • -
  • fromNode and toNode will exist in the tree and will be on the same depth.
    • -
  • toNode is to the right of fromNode.
    • -
  • fromNode.right is null in the initial tree from the test data.
    • + +
  • The number of nodes in the tree is in the range [3, 104].
    • + +
  • -109 <= Node.val <= 109
    • + +
  • All Node.val are unique.
    • + +
  • fromNode != toNode
    • + +
  • fromNode and toNode will exist in the tree and will be on the same depth.
    • + +
  • toNode is to the right of fromNode.
    • + +
  • fromNode.right is null in the initial tree from the test data.
    • +
diff --git a/solution/1700-1799/1725.Number Of Rectangles That Can Form The Largest Square/README_EN.md b/solution/1700-1799/1725.Number Of Rectangles That Can Form The Largest Square/README_EN.md index cbb623295007f..34f00129f2a96 100644 --- a/solution/1700-1799/1725.Number Of Rectangles That Can Form The Largest Square/README_EN.md +++ b/solution/1700-1799/1725.Number Of Rectangles That Can Form The Largest Square/README_EN.md @@ -27,30 +27,45 @@ tags:

Return the number of rectangles that can make a square with a side length of maxLen.

 

+

Example 1:

+
 Input: rectangles = [[5,8],[3,9],[5,12],[16,5]]
+
 Output: 3
+
 Explanation: The largest squares you can get from each rectangle are of lengths [5,3,5,5].
+
 The largest possible square is of length 5, and you can get it out of 3 rectangles.
+

Example 2:

+
 Input: rectangles = [[2,3],[3,7],[4,3],[3,7]]
+
 Output: 3
+

 

+

Constraints:

    -
  • 1 <= rectangles.length <= 1000
    • -
  • rectangles[i].length == 2
    • -
  • 1 <= li, wi <= 109
    • -
  • li != wi
    • + +
  • 1 <= rectangles.length <= 1000
    • + +
  • rectangles[i].length == 2
    • + +
  • 1 <= li, wi <= 109
    • + +
  • li != wi
    • +
diff --git a/solution/1700-1799/1746.Maximum Subarray Sum After One Operation/README_EN.md b/solution/1700-1799/1746.Maximum Subarray Sum After One Operation/README_EN.md index a96cde7d700f3..2ae33ffa3a49c 100644 --- a/solution/1700-1799/1746.Maximum Subarray Sum After One Operation/README_EN.md +++ b/solution/1700-1799/1746.Maximum Subarray Sum After One Operation/README_EN.md @@ -22,26 +22,37 @@ tags:

Return the maximum possible subarray sum after exactly one operation. The subarray must be non-empty.

 

+

Example 1:

+
 Input: nums = [2,-1,-4,-3]
+
 Output: 17
+
 Explanation: You can perform the operation on index 2 (0-indexed) to make nums = [2,-1,16,-3]. Now, the maximum subarray sum is 2 + -1 + 16 = 17.

Example 2:

+
 Input: nums = [1,-1,1,1,-1,-1,1]
+
 Output: 4
+
 Explanation: You can perform the operation on index 1 (0-indexed) to make nums = [1,1,1,1,-1,-1,1]. Now, the maximum subarray sum is 1 + 1 + 1 + 1 = 4.

 

+

Constraints:

    -
  • 1 <= nums.length <= 105
    • -
  • -104 <= nums[i] <= 104
    • + +
  • 1 <= nums.length <= 105
    • + +
  • -104 <= nums[i] <= 104
    • +
diff --git a/solution/1700-1799/1768.Merge Strings Alternately/README_EN.md b/solution/1700-1799/1768.Merge Strings Alternately/README_EN.md index 28ec43946435a..23f19bc99a475 100644 --- a/solution/1700-1799/1768.Merge Strings Alternately/README_EN.md +++ b/solution/1700-1799/1768.Merge Strings Alternately/README_EN.md @@ -24,45 +24,71 @@ tags:

Return the merged string.

 

+

Example 1:

+
 Input: word1 = "abc", word2 = "pqr"
+
 Output: "apbqcr"
+
 Explanation: The merged string will be merged as so:
+
 word1:  a   b   c
+
 word2:    p   q   r
+
 merged: a p b q c r
+

Example 2:

+
 Input: word1 = "ab", word2 = "pqrs"
+
 Output: "apbqrs"
+
 Explanation: Notice that as word2 is longer, "rs" is appended to the end.
+
 word1:  a   b 
+
 word2:    p   q   r   s
+
 merged: a p b q   r   s
+

Example 3:

+
 Input: word1 = "abcd", word2 = "pq"
+
 Output: "apbqcd"
+
 Explanation: Notice that as word1 is longer, "cd" is appended to the end.
+
 word1:  a   b   c   d
+
 word2:    p   q 
+
 merged: a p b q c   d
+

 

+

Constraints:

    -
  • 1 <= word1.length, word2.length <= 100
    • -
  • word1 and word2 consist of lowercase English letters.
    • + +
  • 1 <= word1.length, word2.length <= 100
    • + +
  • word1 and word2 consist of lowercase English letters.
    • +
diff --git a/solution/1700-1799/1788.Maximize the Beauty of the Garden/README_EN.md b/solution/1700-1799/1788.Maximize the Beauty of the Garden/README_EN.md index 8060248067a33..08179c3e044b3 100644 --- a/solution/1700-1799/1788.Maximize the Beauty of the Garden/README_EN.md +++ b/solution/1700-1799/1788.Maximize the Beauty of the Garden/README_EN.md @@ -24,8 +24,11 @@ tags:

A garden is valid if it meets these conditions:

    -
  • The garden has at least two flowers.
    • -
  • The first and the last flower of the garden have the same beauty value.
    • + +
  • The garden has at least two flowers.
    • + +
  • The first and the last flower of the garden have the same beauty value.
    • +

As the appointed gardener, you have the ability to remove any (possibly none) flowers from the garden. You want to remove flowers in a way that makes the remaining garden valid. The beauty of the garden is the sum of the beauty of all the remaining flowers.

@@ -33,36 +36,53 @@ tags:

Return the maximum possible beauty of some valid garden after you have removed any (possibly none) flowers.

 

+

Example 1:

+
 Input: flowers = [1,2,3,1,2]
+
 Output: 8
+
 Explanation: You can produce the valid garden [2,3,1,2] to have a total beauty of 2 + 3 + 1 + 2 = 8.

Example 2:

+
 Input: flowers = [100,1,1,-3,1]
+
 Output: 3
+
 Explanation: You can produce the valid garden [1,1,1] to have a total beauty of 1 + 1 + 1 = 3.
+

Example 3:

+
 Input: flowers = [-1,-2,0,-1]
+
 Output: -2
+
 Explanation: You can produce the valid garden [-1,-1] to have a total beauty of -1 + -1 = -2.
+

 

+

Constraints:

    -
  • 2 <= flowers.length <= 105
    • -
  • -104 <= flowers[i] <= 104
    • -
  • It is possible to create a valid garden by removing some (possibly none) flowers.
    • + +
  • 2 <= flowers.length <= 105
    • + +
  • -104 <= flowers[i] <= 104
    • + +
  • It is possible to create a valid garden by removing some (possibly none) flowers.
    • +
diff --git a/solution/1800-1899/1801.Number of Orders in the Backlog/README_EN.md b/solution/1800-1899/1801.Number of Orders in the Backlog/README_EN.md index 858710a6203f7..fb8b1f0df8967 100644 --- a/solution/1800-1899/1801.Number of Orders in the Backlog/README_EN.md +++ b/solution/1800-1899/1801.Number of Orders in the Backlog/README_EN.md @@ -23,8 +23,11 @@ tags:

You are given a 2D integer array orders, where each orders[i] = [pricei, amounti, orderTypei] denotes that amounti orders have been placed of type orderTypei at the price pricei. The orderTypei is:

    -
  • 0 if it is a batch of buy orders, or
    • -
  • 1 if it is a batch of sell orders.
    • + +
  • 0 if it is a batch of buy orders, or
    • + +
  • 1 if it is a batch of sell orders.
    • +

Note that orders[i] represents a batch of amounti independent orders with the same price and order type. All orders represented by orders[i] will be placed before all orders represented by orders[i+1] for all valid i.

@@ -32,47 +35,79 @@ tags:

There is a backlog that consists of orders that have not been executed. The backlog is initially empty. When an order is placed, the following happens:

    -
  • If the order is a buy order, you look at the sell order with the smallest price in the backlog. If that sell order's price is smaller than or equal to the current buy order's price, they will match and be executed, and that sell order will be removed from the backlog. Else, the buy order is added to the backlog.
    • -
  • Vice versa, if the order is a sell order, you look at the buy order with the largest price in the backlog. If that buy order's price is larger than or equal to the current sell order's price, they will match and be executed, and that buy order will be removed from the backlog. Else, the sell order is added to the backlog.
    • + +
  • If the order is a buy order, you look at the sell order with the smallest price in the backlog. If that sell order's price is smaller than or equal to the current buy order's price, they will match and be executed, and that sell order will be removed from the backlog. Else, the buy order is added to the backlog.
    • + +
  • Vice versa, if the order is a sell order, you look at the buy order with the largest price in the backlog. If that buy order's price is larger than or equal to the current sell order's price, they will match and be executed, and that buy order will be removed from the backlog. Else, the sell order is added to the backlog.
    • +

Return the total amount of orders in the backlog after placing all the orders from the input. Since this number can be large, return it modulo 109 + 7.

 

+

Example 1:

+ + 
+
 Input: orders = [[10,5,0],[15,2,1],[25,1,1],[30,4,0]]
+
 Output: 6
+
 Explanation: Here is what happens with the orders:
+
 - 5 orders of type buy with price 10 are placed. There are no sell orders, so the 5 orders are added to the backlog.
+
 - 2 orders of type sell with price 15 are placed. There are no buy orders with prices larger than or equal to 15, so the 2 orders are added to the backlog.
+
 - 1 order of type sell with price 25 is placed. There are no buy orders with prices larger than or equal to 25 in the backlog, so this order is added to the backlog.
+
 - 4 orders of type buy with price 30 are placed. The first 2 orders are matched with the 2 sell orders of the least price, which is 15 and these 2 sell orders are removed from the backlog. The 3rd order is matched with the sell order of the least price, which is 25 and this sell order is removed from the backlog. Then, there are no more sell orders in the backlog, so the 4th order is added to the backlog.
+
 Finally, the backlog has 5 buy orders with price 10, and 1 buy order with price 30. So the total number of orders in the backlog is 6.
+

Example 2:

+ + 
+
 Input: orders = [[7,1000000000,1],[15,3,0],[5,999999995,0],[5,1,1]]
+
 Output: 999999984
+
 Explanation: Here is what happens with the orders:
+
 - 109 orders of type sell with price 7 are placed. There are no buy orders, so the 109 orders are added to the backlog.
+
 - 3 orders of type buy with price 15 are placed. They are matched with the 3 sell orders with the least price which is 7, and those 3 sell orders are removed from the backlog.
+
 - 999999995 orders of type buy with price 5 are placed. The least price of a sell order is 7, so the 999999995 orders are added to the backlog.
+
 - 1 order of type sell with price 5 is placed. It is matched with the buy order of the highest price, which is 5, and that buy order is removed from the backlog.
+
 Finally, the backlog has (1000000000-3) sell orders with price 7, and (999999995-1) buy orders with price 5. So the total number of orders = 1999999991, which is equal to 999999984 % (109 + 7).
+

 

+

Constraints:

    -
  • 1 <= orders.length <= 105
    • -
  • orders[i].length == 3
    • -
  • 1 <= pricei, amounti <= 109
    • -
  • orderTypei is either 0 or 1.
    • + +
  • 1 <= orders.length <= 105
    • + +
  • orders[i].length == 3
    • + +
  • 1 <= pricei, amounti <= 109
    • + +
  • orderTypei is either 0 or 1.
    • +
diff --git a/solution/1800-1899/1803.Count Pairs With XOR in a Range/README_EN.md b/solution/1800-1899/1803.Count Pairs With XOR in a Range/README_EN.md index 71d734e8f7114..b2f0cba2a3268 100644 --- a/solution/1800-1899/1803.Count Pairs With XOR in a Range/README_EN.md +++ b/solution/1800-1899/1803.Count Pairs With XOR in a Range/README_EN.md @@ -25,42 +25,69 @@ tags:

A nice pair is a pair (i, j) where 0 <= i < j < nums.length and low <= (nums[i] XOR nums[j]) <= high.

 

+

Example 1:

+
 Input: nums = [1,4,2,7], low = 2, high = 6
+
 Output: 6
+
 Explanation: All nice pairs (i, j) are as follows:
+
     - (0, 1): nums[0] XOR nums[1] = 5 
+
     - (0, 2): nums[0] XOR nums[2] = 3
+
     - (0, 3): nums[0] XOR nums[3] = 6
+
     - (1, 2): nums[1] XOR nums[2] = 6
+
     - (1, 3): nums[1] XOR nums[3] = 3
+
     - (2, 3): nums[2] XOR nums[3] = 5
+

Example 2:

+
 Input: nums = [9,8,4,2,1], low = 5, high = 14
+
 Output: 8
+
 Explanation: All nice pairs (i, j) are as follows:
+
 ​​​​​    - (0, 2): nums[0] XOR nums[2] = 13
+
     - (0, 3): nums[0] XOR nums[3] = 11
+
     - (0, 4): nums[0] XOR nums[4] = 8
+
     - (1, 2): nums[1] XOR nums[2] = 12
+
     - (1, 3): nums[1] XOR nums[3] = 10
+
     - (1, 4): nums[1] XOR nums[4] = 9
+
     - (2, 3): nums[2] XOR nums[3] = 6
+
     - (2, 4): nums[2] XOR nums[4] = 5

 

+

Constraints:

    -
  • 1 <= nums.length <= 2 * 104
    • -
  • 1 <= nums[i] <= 2 * 104
    • -
  • 1 <= low <= high <= 2 * 104
    • + +
  • 1 <= nums.length <= 2 * 104
    • + +
  • 1 <= nums[i] <= 2 * 104
    • + +
  • 1 <= low <= high <= 2 * 104
    • +
diff --git a/solution/1800-1899/1808.Maximize Number of Nice Divisors/README_EN.md b/solution/1800-1899/1808.Maximize Number of Nice Divisors/README_EN.md index 043890fcacd1a..d114a92da494e 100644 --- a/solution/1800-1899/1808.Maximize Number of Nice Divisors/README_EN.md +++ b/solution/1800-1899/1808.Maximize Number of Nice Divisors/README_EN.md @@ -23,8 +23,11 @@ tags:

You are given a positive integer primeFactors. You are asked to construct a positive integer n that satisfies the following conditions:

    +
  • The number of prime factors of n (not necessarily distinct) is at most primeFactors.
    • +
  • The number of nice divisors of n is maximized. Note that a divisor of n is nice if it is divisible by every prime factor of n. For example, if n = 12, then its prime factors are [2,2,3], then 6 and 12 are nice divisors, while 3 and 4 are not.
    • +

Return the number of nice divisors of n. Since that number can be too large, return it modulo 109 + 7.

@@ -32,28 +35,41 @@ tags:

Note that a prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. The prime factors of a number n is a list of prime numbers such that their product equals n.

 

+

Example 1:

+
 Input: primeFactors = 5
+
 Output: 6
+
 Explanation: 200 is a valid value of n.
+
 It has 5 prime factors: [2,2,2,5,5], and it has 6 nice divisors: [10,20,40,50,100,200].
+
 There is not other value of n that has at most 5 prime factors and more nice divisors.
+

Example 2:

+
 Input: primeFactors = 8
+
 Output: 18
+

 

+

Constraints:

    -
  • 1 <= primeFactors <= 109
    • + +
  • 1 <= primeFactors <= 109
    • +
diff --git a/solution/1800-1899/1827.Minimum Operations to Make the Array Increasing/README_EN.md b/solution/1800-1899/1827.Minimum Operations to Make the Array Increasing/README_EN.md index af4a7cf20dd88..979e584e8350d 100644 --- a/solution/1800-1899/1827.Minimum Operations to Make the Array Increasing/README_EN.md +++ b/solution/1800-1899/1827.Minimum Operations to Make the Array Increasing/README_EN.md @@ -22,7 +22,9 @@ tags:

You are given an integer array nums (0-indexed). In one operation, you can choose an element of the array and increment it by 1.

    -
  • For example, if nums = [1,2,3], you can choose to increment nums[1] to make nums = [1,3,3].
    • + +
  • For example, if nums = [1,2,3], you can choose to increment nums[1] to make nums = [1,3,3].
    • +

Return the minimum number of operations needed to make nums strictly increasing.

@@ -30,37 +32,55 @@ tags:

An array nums is strictly increasing if nums[i] < nums[i+1] for all 0 <= i < nums.length - 1. An array of length 1 is trivially strictly increasing.

 

+

Example 1:

+
 Input: nums = [1,1,1]
+
 Output: 3
+
 Explanation: You can do the following operations:
+
 1) Increment nums[2], so nums becomes [1,1,2].
+
 2) Increment nums[1], so nums becomes [1,2,2].
+
 3) Increment nums[2], so nums becomes [1,2,3].
+

Example 2:

+
 Input: nums = [1,5,2,4,1]
+
 Output: 14
+

Example 3:

+
 Input: nums = [8]
+
 Output: 0
+

 

+

Constraints:

    -
  • 1 <= nums.length <= 5000
    • -
  • 1 <= nums[i] <= 104
    • + +
  • 1 <= nums.length <= 5000
    • + +
  • 1 <= nums[i] <= 104
    • +
diff --git a/solution/1800-1899/1836.Remove Duplicates From an Unsorted Linked List/README_EN.md b/solution/1800-1899/1836.Remove Duplicates From an Unsorted Linked List/README_EN.md index 22fb099044ee4..e1c623dee2b31 100644 --- a/solution/1800-1899/1836.Remove Duplicates From an Unsorted Linked List/README_EN.md +++ b/solution/1800-1899/1836.Remove Duplicates From an Unsorted Linked List/README_EN.md @@ -22,36 +22,59 @@ tags:

Return the linked list after the deletions.

 

+

Example 1:

+ + 
+
 Input: head = [1,2,3,2]
+
 Output: [1,3]
+
 Explanation: 2 appears twice in the linked list, so all 2's should be deleted. After deleting all 2's, we are left with [1,3].
+

Example 2:

+ + 
+
 Input: head = [2,1,1,2]
+
 Output: []
+
 Explanation: 2 and 1 both appear twice. All the elements should be deleted.
+

Example 3:

+ + 
+
 Input: head = [3,2,2,1,3,2,4]
+
 Output: [1,4]
+
 Explanation: 3 appears twice and 2 appears three times. After deleting all 3's and 2's, we are left with [1,4].
+

 

+

Constraints:

    -
  • The number of nodes in the list is in the range [1, 105]
    • -
  • 1 <= Node.val <= 105
    • + +
  • The number of nodes in the list is in the range [1, 105]
    • + +
  • 1 <= Node.val <= 105
    • +
diff --git a/solution/1800-1899/1857.Largest Color Value in a Directed Graph/README_EN.md b/solution/1800-1899/1857.Largest Color Value in a Directed Graph/README_EN.md index 0aba7a5ebe9a4..d90b69df177ce 100644 --- a/solution/1800-1899/1857.Largest Color Value in a Directed Graph/README_EN.md +++ b/solution/1800-1899/1857.Largest Color Value in a Directed Graph/README_EN.md @@ -32,14 +32,19 @@ tags:

Return the largest color value of any valid path in the given graph, or -1 if the graph contains a cycle.

 

+

Example 1:

+
 Input: colors = "abaca", edges = [[0,1],[0,2],[2,3],[3,4]]
+
 Output: 3
+
 Explanation: The path 0 -> 2 -> 3 -> 4 contains 3 nodes that are colored "a" (red in the above image).
+

Example 2:

@@ -47,21 +52,33 @@ tags: 

+
 Input: colors = "a", edges = [[0,0]]
+
 Output: -1
+
 Explanation: There is a cycle from 0 to 0.
+

 

+

Constraints:

    -
  • n == colors.length
    • -
  • m == edges.length
    • -
  • 1 <= n <= 105
    • -
  • 0 <= m <= 105
    • -
  • colors consists of lowercase English letters.
    • -
  • 0 <= aj, bj < n
    • + +
  • n == colors.length
    • + +
  • m == edges.length
    • + +
  • 1 <= n <= 105
    • + +
  • 0 <= m <= 105
    • + +
  • colors consists of lowercase English letters.
    • + +
  • 0 <= aj, bj < n
    • +
diff --git a/solution/1800-1899/1872.Stone Game VIII/README_EN.md b/solution/1800-1899/1872.Stone Game VIII/README_EN.md index fc84b32817c0f..db273764cb33b 100644 --- a/solution/1800-1899/1872.Stone Game VIII/README_EN.md +++ b/solution/1800-1899/1872.Stone Game VIII/README_EN.md @@ -27,9 +27,13 @@ tags:

There are n stones arranged in a row. On each player's turn, while the number of stones is more than one, they will do the following:

    -
  1. Choose an integer x > 1, and remove the leftmost x stones from the row.
    2. -
  2. Add the sum of the removed stones' values to the player's score.
    3. -
  3. Place a new stone, whose value is equal to that sum, on the left side of the row.
    4. + +
  4. Choose an integer x > 1, and remove the leftmost x stones from the row.
    5. + +
  5. Add the sum of the removed stones' values to the player's score.
    6. + +
  6. Place a new stone, whose value is equal to that sum, on the left side of the row.
    7. +

The game stops when only one stone is left in the row.

@@ -39,48 +43,77 @@ tags:

Given an integer array stones of length n where stones[i] represents the value of the ith stone from the left, return the score difference between Alice and Bob if they both play optimally.

 

+

Example 1:

+
 Input: stones = [-1,2,-3,4,-5]
+
 Output: 5
+
 Explanation:
+
 - Alice removes the first 4 stones, adds (-1) + 2 + (-3) + 4 = 2 to her score, and places a stone of
+
   value 2 on the left. stones = [2,-5].
+
 - Bob removes the first 2 stones, adds 2 + (-5) = -3 to his score, and places a stone of value -3 on
+
   the left. stones = [-3].
+
 The difference between their scores is 2 - (-3) = 5.
+

Example 2:

+
 Input: stones = [7,-6,5,10,5,-2,-6]
+
 Output: 13
+
 Explanation:
+
 - Alice removes all stones, adds 7 + (-6) + 5 + 10 + 5 + (-2) + (-6) = 13 to her score, and places a
+
   stone of value 13 on the left. stones = [13].
+
 The difference between their scores is 13 - 0 = 13.
+

Example 3:

+
 Input: stones = [-10,-12]
+
 Output: -22
+
 Explanation:
+
 - Alice can only make one move, which is to remove both stones. She adds (-10) + (-12) = -22 to her
+
   score and places a stone of value -22 on the left. stones = [-22].
+
 The difference between their scores is (-22) - 0 = -22.
+

 

+

Constraints:

    -
  • n == stones.length
    • -
  • 2 <= n <= 105
    • -
  • -104 <= stones[i] <= 104
    • + +
  • n == stones.length
    • + +
  • 2 <= n <= 105
    • + +
  • -104 <= stones[i] <= 104
    • +
diff --git a/solution/1800-1899/1874.Minimize Product Sum of Two Arrays/README_EN.md b/solution/1800-1899/1874.Minimize Product Sum of Two Arrays/README_EN.md index a072d1144acd3..f4db46805a1ca 100644 --- a/solution/1800-1899/1874.Minimize Product Sum of Two Arrays/README_EN.md +++ b/solution/1800-1899/1874.Minimize Product Sum of Two Arrays/README_EN.md @@ -21,35 +21,51 @@ tags:

The product sum of two equal-length arrays a and b is equal to the sum of a[i] * b[i] for all 0 <= i < a.length (0-indexed).

    -
  • For example, if a = [1,2,3,4] and b = [5,2,3,1], the product sum would be 1*5 + 2*2 + 3*3 + 4*1 = 22.
    • + +
  • For example, if a = [1,2,3,4] and b = [5,2,3,1], the product sum would be 1*5 + 2*2 + 3*3 + 4*1 = 22.
    • +

Given two arrays nums1 and nums2 of length n, return the minimum product sum if you are allowed to rearrange the order of the elements in nums1. 

 

+

Example 1:

+
 Input: nums1 = [5,3,4,2], nums2 = [4,2,2,5]
+
 Output: 40
+
 Explanation: We can rearrange nums1 to become [3,5,4,2]. The product sum of [3,5,4,2] and [4,2,2,5] is 3*4 + 5*2 + 4*2 + 2*5 = 40.
+

Example 2:

+
 Input: nums1 = [2,1,4,5,7], nums2 = [3,2,4,8,6]
+
 Output: 65
+
 Explanation: We can rearrange nums1 to become [5,7,4,1,2]. The product sum of [5,7,4,1,2] and [3,2,4,8,6] is 5*3 + 7*2 + 4*4 + 1*8 + 2*6 = 65.
+

 

+

Constraints:

    -
  • n == nums1.length == nums2.length
    • -
  • 1 <= n <= 105
    • -
  • 1 <= nums1[i], nums2[i] <= 100
    • + +
  • n == nums1.length == nums2.length
    • + +
  • 1 <= n <= 105
    • + +
  • 1 <= nums1[i], nums2[i] <= 100
    • +
diff --git a/solution/1800-1899/1877.Minimize Maximum Pair Sum in Array/README_EN.md b/solution/1800-1899/1877.Minimize Maximum Pair Sum in Array/README_EN.md index 929c483956728..4e50827246f87 100644 --- a/solution/1800-1899/1877.Minimize Maximum Pair Sum in Array/README_EN.md +++ b/solution/1800-1899/1877.Minimize Maximum Pair Sum in Array/README_EN.md @@ -24,45 +24,67 @@ tags:

The pair sum of a pair (a,b) is equal to a + b. The maximum pair sum is the largest pair sum in a list of pairs.

    -
  • For example, if we have pairs (1,5), (2,3), and (4,4), the maximum pair sum would be max(1+5, 2+3, 4+4) = max(6, 5, 8) = 8.
    • + +
  • For example, if we have pairs (1,5), (2,3), and (4,4), the maximum pair sum would be max(1+5, 2+3, 4+4) = max(6, 5, 8) = 8.
    • +

Given an array nums of even length n, pair up the elements of nums into n / 2 pairs such that:

    -
  • Each element of nums is in exactly one pair, and
    • -
  • The maximum pair sum is minimized.
    • + +
  • Each element of nums is in exactly one pair, and
    • + +
  • The maximum pair sum is minimized.
    • +

Return the minimized maximum pair sum after optimally pairing up the elements.

 

+

Example 1:

+
 Input: nums = [3,5,2,3]
+
 Output: 7
+
 Explanation: The elements can be paired up into pairs (3,3) and (5,2).
+
 The maximum pair sum is max(3+3, 5+2) = max(6, 7) = 7.
+

Example 2:

+
 Input: nums = [3,5,4,2,4,6]
+
 Output: 8
+
 Explanation: The elements can be paired up into pairs (3,5), (4,4), and (6,2).
+
 The maximum pair sum is max(3+5, 4+4, 6+2) = max(8, 8, 8) = 8.
+

 

+

Constraints:

    -
  • n == nums.length
    • -
  • 2 <= n <= 105
    • -
  • n is even.
    • -
  • 1 <= nums[i] <= 105
    • + +
  • n == nums.length
    • + +
  • 2 <= n <= 105
    • + +
  • n is even.
    • + +
  • 1 <= nums[i] <= 105
    • +
diff --git a/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md index ecc7532e55269..76cda62341188 100644 --- a/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md +++ b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md @@ -22,47 +22,67 @@ tags:

The alternating sum of a 0-indexed array is defined as the sum of the elements at even indices minus the sum of the elements at odd indices.

    -
  • For example, the alternating sum of [4,2,5,3] is (4 + 5) - (2 + 3) = 4.
    • + +
  • For example, the alternating sum of [4,2,5,3] is (4 + 5) - (2 + 3) = 4.
    • +

Given an array nums, return the maximum alternating sum of any subsequence of nums (after reindexing the elements of the subsequence).

    +

A subsequence of an array is a new array generated from the original array by deleting some elements (possibly none) without changing the remaining elements' relative order. For example, [2,7,4] is a subsequence of [4,2,3,7,2,1,4] (the underlined elements), while [2,4,2] is not.

 

+

Example 1:

+
 Input: nums = [4,2,5,3]
+
 Output: 7
+
 Explanation: It is optimal to choose the subsequence [4,2,5] with alternating sum (4 + 5) - 2 = 7.
+

Example 2:

+
 Input: nums = [5,6,7,8]
+
 Output: 8
+
 Explanation: It is optimal to choose the subsequence [8] with alternating sum 8.
+

Example 3:

+
 Input: nums = [6,2,1,2,4,5]
+
 Output: 10
+
 Explanation: It is optimal to choose the subsequence [6,1,5] with alternating sum (6 + 5) - 1 = 10.
+

 

+

Constraints:

    -
  • 1 <= nums.length <= 105
    • -
  • 1 <= nums[i] <= 105
    • + +
  • 1 <= nums.length <= 105
    • + +
  • 1 <= nums[i] <= 105
    • +
diff --git a/solution/1900-1999/1913.Maximum Product Difference Between Two Pairs/README_EN.md b/solution/1900-1999/1913.Maximum Product Difference Between Two Pairs/README_EN.md index de2987a86b5c6..806f7cb640d4f 100644 --- a/solution/1900-1999/1913.Maximum Product Difference Between Two Pairs/README_EN.md +++ b/solution/1900-1999/1913.Maximum Product Difference Between Two Pairs/README_EN.md @@ -22,7 +22,9 @@ tags:

The product difference between two pairs (a, b) and (c, d) is defined as (a * b) - (c * d).

    -
  • For example, the product difference between (5, 6) and (2, 7) is (5 * 6) - (2 * 7) = 16.
    • + +
  • For example, the product difference between (5, 6) and (2, 7) is (5 * 6) - (2 * 7) = 16.
    • +

Given an integer array nums, choose four distinct indices w, x, y, and z such that the product difference between pairs (nums[w], nums[x]) and (nums[y], nums[z]) is maximized.

@@ -30,30 +32,45 @@ tags:

Return the maximum such product difference.

 

+

Example 1:

+
 Input: nums = [5,6,2,7,4]
+
 Output: 34
+
 Explanation: We can choose indices 1 and 3 for the first pair (6, 7) and indices 2 and 4 for the second pair (2, 4).
+
 The product difference is (6 * 7) - (2 * 4) = 34.
+

Example 2:

+
 Input: nums = [4,2,5,9,7,4,8]
+
 Output: 64
+
 Explanation: We can choose indices 3 and 6 for the first pair (9, 8) and indices 1 and 5 for the second pair (2, 4).
+
 The product difference is (9 * 8) - (2 * 4) = 64.
+

 

+

Constraints:

    -
  • 4 <= nums.length <= 104
    • -
  • 1 <= nums[i] <= 104
    • + +
  • 4 <= nums.length <= 104
    • + +
  • 1 <= nums[i] <= 104
    • +
diff --git a/solution/1900-1999/1914.Cyclically Rotating a Grid/README_EN.md b/solution/1900-1999/1914.Cyclically Rotating a Grid/README_EN.md index fae78135d2d47..2b5a5d14a34c7 100644 --- a/solution/1900-1999/1914.Cyclically Rotating a Grid/README_EN.md +++ b/solution/1900-1999/1914.Cyclically Rotating a Grid/README_EN.md @@ -27,37 +27,59 @@ tags:

A cyclic rotation of the matrix is done by cyclically rotating each layer in the matrix. To cyclically rotate a layer once, each element in the layer will take the place of the adjacent element in the counter-clockwise direction. An example rotation is shown below:

+ +

Return the matrix after applying k cyclic rotations to it.

 

+

Example 1:

+ + 
+
 Input: grid = [[40,10],[30,20]], k = 1
+
 Output: [[10,20],[40,30]]
+
 Explanation: The figures above represent the grid at every state.
+

Example 2:

+ 
+
 Input: grid = [[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]], k = 2
+
 Output: [[3,4,8,12],[2,11,10,16],[1,7,6,15],[5,9,13,14]]
+
 Explanation: The figures above represent the grid at every state.
+

 

+

Constraints:

    -
  • m == grid.length
    • -
  • n == grid[i].length
    • -
  • 2 <= m, n <= 50
    • -
  • Both m and n are even integers.
    • -
  • 1 <= grid[i][j] <= 5000
    • -
  • 1 <= k <= 109
    • + +
  • m == grid.length
    • + +
  • n == grid[i].length
    • + +
  • 2 <= m, n <= 50
    • + +
  • Both m and n are even integers.
    • + +
  • 1 <= grid[i][j] <= 5000
    • + +
  • 1 <= k <= 109
    • +
diff --git a/solution/1900-1999/1915.Number of Wonderful Substrings/README_EN.md b/solution/1900-1999/1915.Number of Wonderful Substrings/README_EN.md index 1db1ec7914388..e6048268f5cc4 100644 --- a/solution/1900-1999/1915.Number of Wonderful Substrings/README_EN.md +++ b/solution/1900-1999/1915.Number of Wonderful Substrings/README_EN.md @@ -24,7 +24,9 @@ tags:

A wonderful string is a string where at most one letter appears an odd number of times.

    -
  • For example, "ccjjc" and "abab" are wonderful, but "ab" is not.
    • + +
  • For example, "ccjjc" and "abab" are wonderful, but "ab" is not.
    • +

Given a string word that consists of the first ten lowercase English letters ('a' through 'j'), return the number of wonderful non-empty substrings in word. If the same substring appears multiple times in word, then count each occurrence separately.

@@ -32,51 +34,83 @@ tags:

A substring is a contiguous sequence of characters in a string.

 

+

Example 1:

+
 Input: word = "aba"
+
 Output: 4
+
 Explanation: The four wonderful substrings are underlined below:
+
 - "aba" -> "a"
+
 - "aba" -> "b"
+
 - "aba" -> "a"
+
 - "aba" -> "aba"
+

Example 2:

+
 Input: word = "aabb"
+
 Output: 9
+
 Explanation: The nine wonderful substrings are underlined below:
+
 - "aabb" -> "a"
+
 - "aabb" -> "aa"
+
 - "aabb" -> "aab"
+
 - "aabb" -> "aabb"
+
 - "aabb" -> "a"
+
 - "aabb" -> "abb"
+
 - "aabb" -> "b"
+
 - "aabb" -> "bb"
+
 - "aabb" -> "b"
+

Example 3:

+
 Input: word = "he"
+
 Output: 2
+
 Explanation: The two wonderful substrings are underlined below:
+
 - "he" -> "h"
+
 - "he" -> "e"
+

 

+

Constraints:

    -
  • 1 <= word.length <= 105
    • -
  • word consists of lowercase English letters from 'a' to 'j'.
    • + +
  • 1 <= word.length <= 105
    • + +
  • word consists of lowercase English letters from 'a' to 'j'.
    • +
diff --git a/solution/1900-1999/1916.Count Ways to Build Rooms in an Ant Colony/README_EN.md b/solution/1900-1999/1916.Count Ways to Build Rooms in an Ant Colony/README_EN.md index 08e8d9fb13bfc..f306ec994eb05 100644 --- a/solution/1900-1999/1916.Count Ways to Build Rooms in an Ant Colony/README_EN.md +++ b/solution/1900-1999/1916.Count Ways to Build Rooms in an Ant Colony/README_EN.md @@ -30,39 +30,65 @@ tags:

Return the number of different orders you can build all the rooms in. Since the answer may be large, return it modulo 109 + 7.

 

+

Example 1:

+ + 
+
 Input: prevRoom = [-1,0,1]
+
 Output: 1
+
 Explanation: There is only one way to build the additional rooms: 0 → 1 → 2
+

Example 2:

+ 
+
 Input: prevRoom = [-1,0,0,1,2]
+
 Output: 6
+
 Explanation:
+
 The 6 ways are:
+
 0 → 1 → 3 → 2 → 4
+
 0 → 2 → 4 → 1 → 3
+
 0 → 1 → 2 → 3 → 4
+
 0 → 1 → 2 → 4 → 3
+
 0 → 2 → 1 → 3 → 4
+
 0 → 2 → 1 → 4 → 3
+

 

+

Constraints:

    -
  • n == prevRoom.length
    • -
  • 2 <= n <= 105
    • -
  • prevRoom[0] == -1
    • -
  • 0 <= prevRoom[i] < n for all 1 <= i < n
    • -
  • Every room is reachable from room 0 once all the rooms are built.
    • + +
  • n == prevRoom.length
    • + +
  • 2 <= n <= 105
    • + +
  • prevRoom[0] == -1
    • + +
  • 0 <= prevRoom[i] < n for all 1 <= i < n
    • + +
  • Every room is reachable from room 0 once all the rooms are built.
    • +
diff --git a/solution/2600-2699/2612.Minimum Reverse Operations/README.md b/solution/2600-2699/2612.Minimum Reverse Operations/README.md index 49a46fe26c70a..f2c06d0e2c4ea 100644 --- a/solution/2600-2699/2612.Minimum Reverse Operations/README.md +++ b/solution/2600-2699/2612.Minimum Reverse Operations/README.md @@ -20,49 +20,60 @@ tags: -

给你一个整数 n 和一个在范围 [0, n - 1] 以内的整数 p ，它们表示一个长度为 n 且下标从 0 开始的数组 arr ，数组中除了下标为 p 处是 1 以外，其他所有数都是 0 。

+

给定一个整数 n 和一个整数 p，它们表示一个长度为 n 且除了下标为 p 处是 1 以外，其他所有数都是 0 的数组 arr。同时给定一个整数数组 banned ，它包含数组中的一些限制位置。在 arr 上进行下列操作：

-

同时给你一个整数数组 banned ，它包含数组中的一些位置。banned 中第 i 个位置表示 arr[banned[i]] = 0 ，题目保证 banned[i] != p 。

+
    +
  • 如果单个 1 不在 banned 中的位置上，反转大小为 k 的 子数组。
    • +
+ +

返回一个包含 n 个结果的整数数组 answer，其中第 i 个结果是将 1 放到位置 i 处所需的 最少 翻转操作次数，如果无法放到位置 i 处，此数为 -1 。

+ +

 

-

你可以对 arr 进行 若干次 操作。一次操作中，你选择大小为 k 的一个 子数组 ，并将它 翻转 。在任何一次翻转操作后，你都需要确保 arr 中唯一的 1 不会到达任何 banned 中的位置。换句话说，arr[banned[i]] 始终 保持 0 。

+

示例 1：

-

请你返回一个数组 ans ，对于 [0, n - 1] 之间的任意下标 i ，ans[i] 是将 1 放到位置 i 处的 最少 翻转操作次数，如果无法放到位置 i 处，此数为 -1 。

+
+

输入：n = 4, p = 0, banned = [1,2], k = 4

+ +

输出：[0,-1,-1,1]

+ +

解释：

    -
  • 子数组 指的是一个数组里一段连续 非空 的元素序列。
    • -
  • 对于所有的 i ，ans[i] 相互之间独立计算。
    • -
  • 将一个数组中的元素 翻转 指的是将数组中的值变成 相反顺序 。
    • +
  • 一开始 1 位于位置 0，因此我们需要在位置 0 上的操作数是 0。
    • +
  • 我们不能将 1 放置在被禁止的位置上，所以位置 1 和 2 的答案是 -1。
    • +
  • 执行大小为 4 的操作以反转整个数组。
    • +
  • 在一次操作后，1 位于位置 3，因此位置 3 的答案是 1。
+
-

 

+

示例 2：

+ +
+

输入：n = 5, p = 0, banned = [2,4], k = 3

+ +

输出：[0,-1,-1,-1,-1]

+ +

解释：

+ +
    +
  • 一开始 1 位于位置 0，因此我们需要在位置 0 上的操作数是 0。
    • +
  • 我们不能在 [0, 2] 的子数组位置上执行操作，因为位置 2 在 banned 中。
    • +
  • 由于 1 不能够放置在位置 2 上，使用更多操作将 1 放置在其它位置上是不可能的。
    • +
+
+ +

示例 3：

+ +
+

输入：n = 4, p = 2, banned = [0,1,3], k = 1

+ +

输出：[-1,-1,0,-1]

+ +

解释：

-

示例 1：

- -
-输入：n = 4, p = 0, banned = [1,2], k = 4
-输出：[0,-1,-1,1]
-解释：k = 4，所以只有一种可行的翻转操作，就是将整个数组翻转。一开始 1 在位置 0 处，所以将它翻转到位置 0 处需要的操作数为 0 。
-我们不能将 1 翻转到 banned 中的位置，所以位置 1 和 2 处的答案都是 -1 。
-通过一次翻转操作，可以将 1 放到位置 3 处，所以位置 3 的答案是 1 。
-
- -

示例 2：

- -
-输入：n = 5, p = 0, banned = [2,4], k = 3
-输出：[0,-1,-1,-1,-1]
-解释：这个例子中 1 一开始在位置 0 处，所以此下标的答案为 0 。
-翻转的子数组长度为 k = 3 ，1 此时在位置 0 处，所以我们可以翻转子数组 [0, 2]，但翻转后的下标 2 在 banned 中，所以不能执行此操作。
-由于 1 没法离开位置 0 ，所以其他位置的答案都是 -1 。
-
- -

示例 3：

- -
-输入：n = 4, p = 2, banned = [0,1,3], k = 1
-输出：[-1,-1,0,-1]
-解释：这个例子中，我们只能对长度为 1 的子数组执行翻转操作，所以 1 无法离开初始位置。
-
+

执行大小为 1 的操作，且 1 永远不会改变位置。

+