#include <bits/stdc++.h>
using namespace std;
int n;
int a[45];
int cnt;
int vis[4005];
int l,r;
void f(int k,int sum)
{
	vis[sum]++;
	if(k == n)
	{
		return;
	}
	f(k+1,sum+a[k+1]);
	f(k+1,sum);
}
int main()
{
	cin >> n >> l >> r;
	for(int i = 1;i<=n;i++)
	{
		cin >> a[i];
	}
	f(0,0);
	int cnt = 0;
	for(int i = l;i<=r;i++)
	{
		if(vis[i]>0)
		{
			cnt+=vis[i];
		}
	}
	cout << cnt;
    return 0;
}

为什么0分，大佬求助！！