LeetCode Minimum Depth of Binary Tree

题目

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.

求二叉树的最小深度，递归即可。

代码

/**
* 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)	//空
return 0;
if(root->left==NULL&&root->right==NULL)	//叶节点
return 1;
if(root->left==NULL)	//左子树为空
return minDepth(root->right)+1;
if(root->right==NULL)	//右子树为空
return minDepth(root->left)+1;
return min(minDepth(root->left),minDepth(root->right))+1;	//一般情况
}
};