소프트웨어에 대한 모든 것

1302. Deepest Leaves Sum https://leetcode.com/problems/deepest-leaves-sum/ Deepest Leaves Sum - LeetCode Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 문제) 솔루션1) hashtable을 사용해서 각 depth의 노드에 해당하는 모든 val 값들을 list 형태로 저장한다. hashtable에서 최대 depth에 O(1)로 접근해서 모든 values의 sum을 구하면 그것이 deepest lea..

226. Invert Binary Tree 문제) Given the root of a binary tree, invert the tree, and return its root. 솔루션1) # Definition for a binary tree node. # class TreeNode: # def __init__(self, val=0, left=None, right=None): # self.val = val # self.left = left # self.right = right class Solution: def invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]: self.invert(root) return root def invert(se..