leetcode--Minimum Depth of Binary Tree

1.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.

2.解法分析

/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int minDepth(TreeNode *root) { // Start typing your C/C++ solution below // DO NOT write int main() function if(root == NULL)return 0; if(!root->left&&!root->right)return 1; if(root->left&&root->right) { return min(minDepth(root->left),minDepth(root->right))+1; } else { if(root->left)return minDepth(root->left)+1; else return minDepth(root->right)+1; } } };