104. Maximum Depth of Binary Tree

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

题意：求二叉树的树高。

思路：递归求解。

/**
* 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 maxDepth(TreeNode* root) {
if (root == NULL)
return 0;
else{
int left, right;
left = maxDepth(root->left) + 1;
right = maxDepth(root->right) + 1;
return left > right ? left : right;
}
}
};