counting number of subtrees with given sum

/*
Given a binary tree containing N+1 with N edges nodes and an integer X. Your task is to complete the function countSubtreesWithSumX() 
that returns the count of the number of subtress having total node’s data sum equal to a value X.

 Example: For the tree given below:            

              5
            /    \
        -10     3
        /    \    /  \
      9     8  -4 7

Subtree with sum 7:
             -10
            /      \
          9        8

and one node 7.

Input:
First line of input contains number of testcases T. For each testcase, first line of input contains number of edges in the tree. Next 
line contains information as X Y L or X Y R which means Y is on the left of X or Y is on the right of X respectively. Last line contains
sum.

Output:
For each test case count the number of subtrees with given sum.

Your Task:
The task is to complete the function countSubtreesWithSumX() which check if there exists a subtree with sum x.

Constraints:
1 <= T <= 103
1 <= N <= 103
-103 <= Node Value <= 103

Example:
Input:
2
6
5 -10 L 5 3 R -10 9 L -10 8 R 3 -4 L 3 7 R
7
2
1 2 L 1 3 R
5

Output:
2
0

Explanation:
Testcase 1: Subtrees with sum 7 are [9, 8, -10] and [7].
*/


int value(Node* root,int x,int &count)
{
if(root==NULL)
return 0;
int s1=value(root->left,x,count);
int s2=value(root->right,x,count);
if(s1+s2+root->data==x)
count++;

}
int countSubtreesWithSumX(Node* root, int x)
{
if(root==NULL)
return 0;
int count=0;
value(root,x,count);
return count;
}