LeetCode: Balanced Binary Tree

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 binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
bool isBalanced(TreeNode *root) {
flag = true;
getDepth(root);
return flag;
}
private:
bool flag;
int getDepth(TreeNode * node)
{
if(node == NULL)
return 0;
int depthL = getDepth(node->left);
int depthR = getDepth(node->right);
if(depthL - depthR > 1 || depthL - depthR < -1)
flag = false;
return std::max(depthL, depthR) + 1;
}
};