# [LintCode] Maximum Depth of Binary Tree 二叉树的最大深度

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.

Example

Given a binary tree as follow:

1
/ \
2   3
/ \
4   5

The maximum depth is 3.

LeetCode上的原题，请参见我之前的博客Maximum Depth of Binary Tree

class Solution {
public:
/**
* @param root: The root of binary tree.
* @return: An integer
*/
int maxDepth(TreeNode *root) {
if (!root) return 0;
return 1 + max(maxDepth(root->left), maxDepth(root->right));
}
};

class Solution {
public:
/**
* @param root: The root of binary tree.
* @return: An integer
*/
int maxDepth(TreeNode *root) {
if (!root) return 0;
int res = 0;
queue<TreeNode*> q;
q.push(root);
while(!q.empty()) {
++res;
int n = q.size();
for (int i = 0; i < n; ++i) {
TreeNode *t = q.front(); q.pop();
if (t->left) q.push(t->left);
if (t->right) q.push(t->right);
}
}
return res;
}
};

posted @ 2016-11-13 06:08 Grandyang 阅读(...) 评论(...) 编辑 收藏