feat: add 100 leetcode hot100 problem folders with solution scaffolding

3sum/solution.py

@@ -0,0 +1,37 @@
+# https://leetcode.cn/problems/3sum/
+
+
+class Solution:
+    def threeSum(self, nums: list[int]) -> list[list[int]]:
+        n = len(nums)
+        res = []
+        nums.sort()
+
+        for i in range(n - 2):
+            if i > 0 and nums[i] == nums[i - 1]:
+                continue
+            left, right = i + 1, n - 1
+            if nums[i] > 0 or nums[right] < 0:
+                continue
+            while left < right:
+                sum = nums[i] + nums[left] + nums[right]
+                if sum > 0:
+                    right -= 1
+                elif sum < 0:
+                    left += 1
+                    continue
+                if sum == 0:
+                    res.append([nums[i], nums[left], nums[right]])
+                    left += 1
+                    while left < right and nums[left - 1] == nums[left]:
+                        left += 1
+                    right -= 1
+                    while left < right and nums[right] == nums[right + 1]:
+                        right -= 1
+
+        return res
+
+
+if __name__ == "__main__":
+    res = Solution().threeSum([-1, 0, 1, 2, -1, -4])
+    print(res)