/**
 * 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:
    int sum(TreeNode *root , int h)
    {
        if(!root) return 0;
        if(root->left == NULL && root->right == NULL)
        {
            return root->val * h;
        }
        int w_l , w_r;
        w_l = sum(root->left , h + 1) , w_r = sum(root->right , h + 1);
        return w_l + w_r;
    }

    int pathSum(TreeNode* root) {
        return sum(root , 0);
    }
};