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.

class Solution {
public:
    bool f(TreeNode *root, int & height){
        if (!root){
            height = 0;
            return true;
        }
        int left_h = 0, right_h = 0;
        bool left_c = f(root->left,left_h);
        bool right_c = f(root->right,right_h);
        height = max(left_h,right_h) + 1;
        return left_c && right_c && abs(left_h - right_h) <= 1;
    }
    bool isBalanced(TreeNode *root) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int height = 0;
        return f(root,height);
    }
};