daily leetcode - minimum-depth-of-binary-tree - !
题目地址 https://leetcode.com/problems/minimum-depth-of-binary-tree/ 题目描述 Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. Note: A leaf is a node with no children. Example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its minimum depth = 2. 思路 二叉树的经典问题之最小深度问题就是就最短路径的节点个数,还是用深度优先搜索 DFS 来完成,万能的递归啊。首先判空,若当前结点不存在,直接返回 0。然后看若左子结点不存在,那么对右子结点调用递归函数,并加 1 返回。反之,若右子结点不存在,那么....