[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

/**
 * 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) {
        if(root==NULL) return 0;
        if(root->left==NULL && root->right==NULL) return 1;
        
        int Leftdepth = minDepth(root->left);
        int Rightdepth = minDepth(root->right);
    
        if(Leftdepth==0)
            return Rightdepth+1;
        else if(Rightdepth==0)
            return Leftdepth+1;

        return min(Leftdepth,Rightdepth)+1;
    }
};