[LeetCode] 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.
用DFS搞定
1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right; 7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {} 8 * }; 9 */ 10 class Solution { 11 public: 12 int maxDepth(TreeNode *root) { 13 // Start typing your C/C++ solution below 14 // DO NOT write int main() function 15 if (root == NULL) 16 return 0; 17 18 int leftDepth = maxDepth(root->left); 19 int rightDepth = maxDepth(root->right); 20 21 return max(leftDepth, rightDepth) + 1; 22 } 23 };