Balanced Binary Tree

Desicription

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

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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 {
private:
int depth(TreeNode* root) {
if(root == NULL)
return 0;
return max(depth(root->left), depth(root->right)) + 1;
}
public:
bool isBalanced(TreeNode* root) {
if(root == NULL)
return 1;
int left = depth(root->left);
int right = depth(root->right);
return (abs(left-right) <= 1) && isBalanced(root->left) && isBalanced(root->right);
}
};