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.
Note: A leaf is a node with no children.
Example:
Given binary tree [3,9,20,null,null,15,7]
,
3 / \ 9 20 / \ 15 7
return its depth = 3.
递归求二叉树的最大深度
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
int maxDepth(TreeNode* root) {
int res=0,res1,res2;
TreeNode *t;
t=root;
if(t!=NULL)
{
res++;
res1=maxDepth(t->left);
res2=maxDepth(t->right);
if(res1>res2)
res=res+res1;
else
res=res+res2;
}
return res;
}
};