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 status;
    int helper(TreeNode * node){
        if (node==NULL){
            return 0;
        }
        else {
            int leftdepth = helper(node->left);
            int rightdepth = helper(node->right);
            
            int dif = leftdepth - rightdepth;
            dif = dif>0?dif:-dif;
            if (dif>1)
                status = false;
            
            return max(leftdepth, rightdepth)+1;
        }
    }
    bool isBalanced(TreeNode *root) {
        status = true;
        
        helper(root);
        
        return status;
    }
};