leetcode--111. 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.

题解

和求最大深度类似，不过求最小深度需要注意的是，当一个节点只有左子树或者右子树的时候，不应取最小的那个作为深度。

/**
* Definition for a binary tree node.
* 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;
int L = minDepth(root->left), R = minDepth(root->right);
return 1 + (min(L, R) ? min(L, R) : max(L, ;R))
}
};