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.
/**
* 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:
inline int max(int a, int b){
return a > b ? a : b;
}
inline int abs(int x){
return x >= 0 ? x : -x;
}
int subtreeDepth(TreeNode* root){
if(NULL == root) return 0;
else return 1 + max(subtreeDepth(root->left), subtreeDepth(root->right));
}
bool isBalanced(TreeNode* root) {
if(NULL == root) return true;
return abs(subtreeDepth(root->left) - subtreeDepth(root->right)) <= 1 &&
isBalanced(root->left) &&
isBalanced(root->right);
}
};
