leetcode 104

Maximum Depth of Binary Tree

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.

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

};