1.描述

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.

2.分析

3.代码

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
int maxDepth(struct TreeNode* root) {
    if (NULL == root) return 0;
    if (NULL == root->left && NULL == root->right) return 1;
    int left = maxDepth(root->left);
    int right = maxDepth(root->right);
    return left > right ? left+1 : right+1;
}