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],

return its depth = 3.

 

 

很简单的二叉树题目，直接看代码就ok了。

int maxDepth(struct TreeNode* root) {        if(root==NULL) return 0;    if(root->left==NULL&&root->right==NULL)        return 1;    else if(root->left!=NULL&&root->right==NULL)        return maxDepth(root->left)+1;    else if(root->left==NULL&&root->right!=NULL)        return maxDepth(root->right)+1;    else        return _max(maxDepth(root->left)+1,maxDepth(root->right)+1);    }int _max(int a,int b){    if(a>b)        return a;    else        return b;}