Равенство, перебор

#include <iostream>
#include <algorithm>
#include <string>
#include <vector>

using namespace std;

vector < int > x;

int solve(int idx, long long sum) {
    if (idx == 0 && sum == 0) {
        return 1;
    }
    if (idx == 0) {
        return 0;
    }
    long long res = 1;
    int cnt = 0;
    for (int i = idx - 1; i >= 0; --i) {
        res *= x[i];
        if (sum >= res) {
            cnt += solve(i, sum - res);
        } else {
            break;
        }
    }
    return cnt;
}
int main() {
    int n, sum;
    cin >> n >> sum;
    x.resize(n);
    for (int i = 0; i < n; ++i) {
        cin >> x[i];
    }
    cout << solve(x.size(), sum);
    return 0;
}