[LeetCode 题解]: Minimum Depth of Binary Tree

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.

题意很清楚，找到二叉树中深度最短的一条路径，DFS（貌似是面试宝典上的一道题）

类似的一道题：http://www.cnblogs.com/double-win/p/3737262.html

 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     int minDepth(TreeNode *root) {
13         if(root==NULL) return 0;
14         if(root->left==NULL && root->right==NULL) return 1;
15         
16         int Leftdepth = minDepth(root->left);
17         int Rightdepth = minDepth(root->right);
18     
19         if(Leftdepth==0)
20             return Rightdepth+1;
21         else if(Rightdepth==0)
22             return Leftdepth+1;
23 
24         return min(Leftdepth,Rightdepth)+1;
25     }
26 };