Balanced Binary Tree [LeetCode]

Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.

Solution: 

 1     bool helperBalanced(int *depth, TreeNode * root){
 2         if(root->left == NULL && root->right == NULL){
 3             (*depth) = 1;
 4             return true;
 5         }
 6         
 7         int left_depth = 0;
 8         int right_depth = 0;
 9         if(root->left != NULL){
10             if(helperBalanced(&left_depth, root->left) == false)
11                 return false;
12         }
13         
14         if(root->right != NULL){
15             if(helperBalanced(&right_depth, root->right) == false)
16                 return false;
17         }
18         
19         if(abs(right_depth - left_depth) > 1)
20             return false;
21         
22         (*depth) = max(left_depth, right_depth) + 1;
23             
24         return true;
25     }
26     
27     bool isBalanced(TreeNode *root) {
28         if(root == NULL)
29             return true;
30         int depth= 0;
31         return helperBalanced(&depth, root);
32     }

 

posted @ 2013-11-29 07:22  假日笛声  阅读(184)  评论(0)  编辑  收藏  举报