Distribute candies in a binary tree.cpp

class Solution 
{ 
    public: 
    int help(Node* root,int& ans) 
    { 
        
        if(!root) 
        return 0; 
         
        
        int left=help(root->left,ans); 
        int right=help(root->right,ans); 
         
        ans+=abs(left)+abs(right); 
         
        return root->key+left+right-1; 
    } 
    int distributeCandy(Node* root) 
    { 
        int ans=0; 
        int call=help(root,ans); 
        return ans; 
    } 
};