Add solution and test-cases for problem 3397

Author: 0xff-dev

leetcode/3301-3400/3397.Maximum-Number-of-Distinct-Elements-After-Operations/README.md

@@ -1,28 +1,37 @@
 # [3397.Maximum Number of Distinct Elements After Operations][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+You are given an integer array `nums` and an integer `k`.
+
+You are allowed to perform the following **operation** on each element of the array **at most** once:
+
+- Add an integer in the range `[-k, k]` to the element.
+
+Return the **maximum** possible number of **distinct** elements in `nums` after performing the **operations**.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
-```
+Input: nums = [1,2,2,3,3,4], k = 2
 
-## 题意
-> ...
+Output: 6
 
-## 题解
+Explanation:
 
-### 思路1
-> ...
-Maximum Number of Distinct Elements After Operations
-```go
+nums changes to [-1, 0, 1, 2, 3, 4] after performing operations on the first four elements.
 ```
 
+**Example 2:**
+
+```
+Input: nums = [4,4,4,4], k = 1
+
+Output: 3
+
+Explanation:
+
+By adding -1 to nums[0] and 1 to nums[1], nums changes to [3, 5, 4, 4].
+```
 
 ## 结语
 

leetcode/3301-3400/3397.Maximum-Number-of-Distinct-Elements-After-Operations/Solution.go

@@ -1,5 +1,21 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import (
+	"math"
+	"sort"
+)
+
+func Solution(nums []int, k int) int {
+	sort.Ints(nums)
+	cnt := 0
+	prev := math.MinInt32
+
+	for _, num := range nums {
+		curr := min(max(num-k, prev+1), num+k)
+		if curr > prev {
+			cnt++
+			prev = curr
+		}
+	}
+	return cnt
 }

leetcode/3301-3400/3397.Maximum-Number-of-Distinct-Elements-After-Operations/Solution_test.go

@@ -10,30 +10,30 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs []int
+		k      int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 2, 2, 3, 3, 4}, 2, 6},
+		{"TestCase2", []int{4, 4, 4, 4}, 1, 3},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.inputs, c.k)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.inputs, c.k)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }