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.
解决树的问题很大一部分都是可以用递归来做的。
1 class Solution { 2 public: 3 int maxDepth(TreeNode *root) { 4 if(root == NULL) 5 return 0; 6 int rdepth = maxDepth(root->right); 7 int ldepth = maxDepth(root->left); 8 return rdepth>ldepth?rdepth+1:ldepth+1; 9 } 10 };