Kortit II

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

const int MOD = 1000000007;

long long factorial(int n) {
    long long result = 1;
    for (int i = 1; i <= n; i++) {
        result = (result * i) % MOD;
    }
    return result;
}

int main() {
    int t;
    std::cin >> t;
    std::vector<int> Ns(t), As(t), Bs(t);

    for (int i = 0; i < t; i++) {
        std::cin >> Ns[i] >> As[i] >> Bs[i];
    }

    for (int test = 0; test < t; test++) {
        int n = Ns[test];
        int a = As[test];
        int b = Bs[test];

        if (a + b == 1 || a + b > n) {
            std::cout << 0 << std::endl;
            continue;
        }

        int possibles = 0;
        std::vector<int> perm(n);
        for (int i = 0; i < n; i++) perm[i] = i;
        do {
            int A = 0, B = 0;
            for (int i = 0; i < n; i++) {
                if (perm[i] - i < 0)
                    A++;
                else if (perm[i] - i > 0)
                    B++;
            }

            if (A == a && B == b) {
                possibles++;
            }
        } while (std::next_permutation(perm.begin(), perm.end()));

        long long result = (possibles * factorial(n)) % MOD;
        std::cout << result << std::endl;
    }

    return 0;
}

Test 1

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

Test 2

Group: 2, 3, 4, 5

Verdict: ACCEPTED

Test 3

Group: 3, 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 5

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 5

Verdict: TIME LIMIT EXCEEDED