104. Maximum Depth of Binary Tree
题目
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.
解析
// Maximum Depth of Binary Tree
class Solution {
public:
// Time Limit Exceeded
int maxDepth1(TreeNode *root) {
if (!root)
{
return 0;
}
return (maxDepth(root->left) > maxDepth(root->right)) ? (maxDepth(root->left) + 1) : (maxDepth(root->right)+1);
}
// 这样写不会超时
int maxDepth(TreeNode* root) {
if (root == NULL)
return 0;
return max(maxDepth(root->left), maxDepth(root->right)) + 1;
}
int maxDepth(TreeNode *root)
{
if (!root)
{
return 0;
}
queue<TreeNode*> que;
que.push(root);
int level = 0;
while (!que.empty())
{
int size = que.size();
for (int i = 0; i < size;i++)
{
TreeNode* temp = que.front();
que.pop();
if (temp->left)
{
que.push(temp->left);
}
if (temp->right)
{
que.push(temp->right);
}
}
level++;
}
return level;
}
};