LeetCode: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.

 

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