Sorting old Qs + ZigZag + tests

.github/workflows/build-and-test.yml

@@ -0,0 +1,26 @@
+name: Python Tests
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: [3.8, 3.9]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Run tests
+      run: |
+          python -m unittest discover

ProblemsByTags.json

@@ -7,6 +7,9 @@
             "ThreeSum",
             "TopKFrequentNums"
         ],
+        "Extreme": [
+            "FirstMissingPositive"
+        ],
         "Hard": [
             "Codec",
             "LongestPalindrome",
@@ -49,6 +52,7 @@
             "ThreeSum"
         ],
         "Sorting": [
+            "FirstMissingPositive",
             "SortColors"
         ],
         "Strings": [

README.md

@@ -48,7 +48,7 @@ Please make sure to replace everything need to be replaced.
 
 Add a few test cases, make sure they're running smoothly.
 
-Run `.\build.ps1`.
+Run `python ProblemsByTags.py`.
 If everything is OK, push it and open a PR.
 
 ## Troubleshooting

Solutions/F/FirstMissingPositive.py

@@ -0,0 +1,55 @@
+import unittest
+from Tags import *
+
+"""
+Author: Jonathan Joseph
+Problem Description/link: replace with relevant link or problem description
+"""
+
+
+class Solution(object):
+    def getTags(self):
+        tags = [Difficulty.Extreme, Topic.Sorting]
+        return tags
+
+    def firstMissingPositive(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+
+        if not nums:
+            return 1
+
+        ptr = 0
+        junk = len(nums)
+
+        while ptr < junk:
+            if nums[ptr] == ptr + 1:
+                ptr += 1
+                continue
+
+            if nums[ptr] <= 0 or nums[ptr] >= junk or nums[ptr] == nums[nums[ptr] - 1]:
+                junk -= 1
+                nums[ptr], nums[junk] = nums[junk], nums[ptr]
+                continue
+
+            temp = nums[nums[ptr] - 1]
+            nums[nums[ptr] - 1] = nums[ptr]
+            nums[ptr] = temp
+
+        for i in range(len(nums)):
+            if nums[i] != i + 1:
+                return i + 1
+
+        return len(nums) + 1
+
+
+class test_firstMissingPositive(unittest.TestCase):
+    def test_1(self):
+        self.assertEqual(2, Solution().firstMissingPositive([3, 3, 1, 4, 0]))
+        self.assertEqual(1, Solution().firstMissingPositive([3, -7, 2, 4, 0]))
+        self.assertEqual(6, Solution().firstMissingPositive([1, 2, 3, 5, 4]))
+        self.assertEqual(1, Solution().firstMissingPositive([-7]))
+        self.assertEqual(1, Solution().firstMissingPositive([]))
+        self.assertEqual(2, Solution().firstMissingPositive([1, 1, 1, 1, 1, 1, 1, 1]))

Solutions/Z/ZigzagConversion.py

@@ -0,0 +1,50 @@
+import unittest
+from Tags import *
+"""
+Author: Jonathan Joseph
+Problem Description/link: replace with relevant link or problem description
+"""
+
+class Solution(object):
+    def getTags(self):
+        tags = [Difficulty.Hard, Topic.Strings]
+        return tags
+
+    def convert(self, s, numRows):
+        """
+        :type s: str
+        :type numRows: int
+        :rtype: str
+        """
+        if numRows == 1:
+            return s
+
+        res = ''
+        delta = (2*(numRows-1))
+
+        for r in range(numRows):
+            if r == 0 or r == numRows - 1:
+                i = r
+                while i < len(s):
+                    res += s[i]
+                    i += delta
+
+            else:
+                indices = [r, delta-r]
+                i = 0
+                while indices[i] < len(s):
+                    res += s[indices[i]]
+                    indices[i] += delta
+                    i = ((i+1) % len(indices))
+
+        return res
+
+
+
+class test_zigzagConversion(unittest.TestCase):
+    def test_1(self):
+        self.assertEqual(Solution().convert("PAYPALISHIRING", 3), "PAHNAPLSIIGYIR")
+        self.assertEqual(Solution().convert("PAYPALISHIRING", 4), "PINALSIGYAHRPI")
+        self.assertEqual(Solution().convert("PAYPALISHIRING", 1), "PAYPALISHIRING")
+        self.assertEqual(Solution().convert("ABCD", 3), "ABDC")
+        self.assertEqual(Solution().convert("a", 7), "a")