Fetching contributors…
Cannot retrieve contributors at this time
57 lines (56 sloc) 1.31 KB
 /* * @lc app=leetcode.cn id=111 lang=cpp * * [111] 二叉树的最小深度 * * https://leetcode-cn.com/problems/minimum-depth-of-binary-tree/description/ * * algorithms * Easy (36.51%) * Total Accepted: 10.5K * Total Submissions: 28.6K * Testcase Example: '[3,9,20,null,null,15,7]' * * 给定一个二叉树，找出其最小深度。 * * 最小深度是从根节点到最近叶子节点的最短路径上的节点数量。 * * 说明: 叶子节点是指没有子节点的节点。 * * 示例: * * 给定二叉树 [3,9,20,null,null,15,7], * * ⁠ 3 * ⁠ / \ * ⁠ 9 20 * ⁠ / \ * ⁠ 15 7 * * 返回它的最小深度  2. * */ /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ //dfs.递归。E class Solution { public: int minDepth(TreeNode* root) { //root==nullptr,0 if(!root) return 0; //left==nullptr->f(right)+1 if(!root->left) return 1+minDepth(root->right); //right==nullptr->f(left)+1 if(!root->right) return 1+minDepth(root->left); //none of above==nullptr->min(f(left),f(right))+1 return 1+min(minDepth(root->left),minDepth(root->right)); } };
You can’t perform that action at this time.