全wa求助

#include <iostream>
using namespace std;
int n, l, r, ans;
int w[50];
bool a[50];

void dfs(int step, int sum) {
    if (step > n) {
        if (sum >= l && sum <= r) {
            ans++;
            return ;
        }
    }
    if (sum > r)
        return;

    for (int i = step; i <= n; i++) {
        if (a[i] == 0) {
            a[i] = 1;
            sum += w[i];
            dfs(i + 1, sum);
            a[i] = 0;
            sum -= w[i];
        }
    }
}

int main() {
    cin >> n >> l >> r;
    for (int i = 1; i <= n; i++) {
        cin >> w[i];
    }
    dfs(1, 0);
    cout << ans;
    return 0;
}