fix:四数之和

01-数组/day04/problem_solving_10.py

+"""
+四数之和
+"""
+from typing import List
+
+
+class Solution:
+    def fourSum(self, nums: List[int], target: int) -> List[List[int]]:
+        """
+        四数之和 转化为三数之和,理清楚第一个数和第二个之间的关系
+        :param nums:
+        :param target:
+        :return:
+        """
+        nums.sort()
+        res = []
+        n = len(nums)
+        for i in range(n - 3):
+            if i > 0 and nums[i] == nums[i - 1]:
+                continue
+            for j in range(i + 1, n - 2):
+                if j > i + 1 and nums[j] == nums[j - 1]:
+                    continue
+                left, right = j + 1, n - 1
+                while left < right:
+                    s = nums[i] + nums[j] + nums[left] + nums[right]
+                    if s == target:
+                        res.append([nums[i], nums[j], nums[left], nums[right]])
+                        while left < right and nums[left] == nums[left + 1]:
+                            left += 1
+                        while left < right and nums[right] == nums[right - 1]:
+                            right -= 1
+                        left += 1
+                        right -= 1
+                    elif s > target:
+                        right -= 1
+                    else:
+                        left += 1
+        return res
+
+
+if __name__ == '__main__':
+    result = Solution().fourSum([1, 0, -1, 0, -2, 2], 0)
+    print(result)

03-二叉树/problem_solving_01.py

+"""
+在二叉树中分配硬币
+"""
+
+from typing import List, Optional
+
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+
+class Solution:
+    def distributeCoins(self, root: Optional[TreeNode]) -> int:
+        pass
+
+
+if __name__ == '__main__':
+    result = Solution().distributeCoins(3, 0, 0)
+    print(result)