Kortit II

#include <algorithm>
#include <bits/stdc++.h>

using namespace std;

long mod = 1000000000 + 7;

int fc(int factor) { //factorial
  int answer = 1;
  for (long i = 1; i <= factor; i++) {
    answer *= i;
  }
  return answer;
}

long fcm(int factor) { //factorial
  long answer = 1;
  for (long i = 1; i <= factor; i++) {
    answer = (answer % mod * i % mod) % mod;
  }
  return answer;
}

vector<long> createNumberLine(int n) {
  vector<long> answer = {};
  for (long i = 1; i <= n; i++) {
    answer.push_back(i);
  }
  return answer;
}

vector<vector<long>> testInput(int amt) {
  vector<vector<long>> answer = {};
  int a = 1;
  int b = 1;
  int n = 1;
  for (int i = 1; i <= amt*amt*amt; i++) {
    if (a % amt == 1 && a != 1) {
      a = 1;
      b++;
      if (b % amt == 1 && b != 1) {
      b = 1;
      n++;
      }
    }
    answer.push_back({n, a, b});
    cout << n << " " << a << " " << b << "\n";
    a++;
  }
  return answer;
}

string printFactor(int n) {
  string answer = "1";
  for (int i = 2 ; i <= n; i++) {
    answer += "*" + to_string(i);
  }
  return answer;
}  

void printArray(vector<long> a) {
  for (int i = 0; i < (int)a.size(); i++) {
    cout << a[i] << " ";
  }
  cout << "\n";
}

long bruteForce(int n, int a, int b) {
  long p = 0;
  vector<long> l1 = createNumberLine(n);
  vector<long> l2 = createNumberLine(n);
  for (int i = 1; i <= fc(n); i++) {
    for (int j = 1; j <= fc(n); j++) {
      int a1 = 0;
      int b1 = 0;
      for (int k = 0; k < n; k++) {
        if (l1[k] > l2[k]) {
          a1++;
        } else if (l2[k] > l1[k]) {
          b1++;
        }
      }
      if (a1 == a && b1 == b) {
        p++;
      }
      next_permutation(l2.begin(), l2.end());
    }
    next_permutation(l1.begin(), l1.end());
  }
  return p;
}

string isCorrect(long answer, int n, int a, int b) {
  long bf = bruteForce(n, a, b);
  if (answer == bf) {
    return "true " + to_string(bf);
  } else {
    return "false A: " + to_string(answer) + " | BF: " + to_string(bf) + " " + to_string(n) + " " + to_string(a) + " " + to_string(b);
  }
}

// d kertaa -> 1+2+3 ja 1+2 ja 1
long sumOfSums(int d, int n) {
  /*long answer = 0;
  for (int i = 1; i <= n-d+1; i++) {
    int x = n-i-1;
    answer += x*(x+1)/2;
    string test = "1";
    for (int j = 2; j <= x; j++) {
      test += "+" + to_string(j);
    }
    cout << test << endl;
  }
  return (answer != 0) ? answer : 1;*/
  return (fcm(n)%mod)/((fcm(d)%mod)*(fcm(n-d)%mod));
}

int main() {
  /*int a = 0;
  int n = 0;
  cout << "n, a: ";
  cin >> n >> a;
  int ap = 0; //a permutations
  for (int i = 1; i <= n; i++) {
    int d = n-i; // Vaikutusalue
    if (d >= a) { //kertolasku amt: a-1 ja summa amt: d-a+1
      int sum = (d-a+1 != 0) ? d-a+1 : 1;
      ap += (fc(n-i)/fc(sum))*((sum*(sum+1)/2));
      cout << "x: " << i << " ap: " << factortest(n-i) << "/" << factortest(sum) << " sum: " << sumtest(sum) << endl;
      cout << "ap: " << (fc(n-i)/fc(sum))*((sum*(sum+1)/2)) << endl;
    } else {
      continue; //break; ??
    }
  }
  cout << ap;*/

  /*cout << sumOfSums(2, 4) << endl;
  return 0;*/

  long t;
  vector<vector<long>> g;
  cin >> t;
  for (long i = 0; i < t; i++) {
    long n, a, b;
    cin >> n >> a >> b;
    long d = n-(a+b); //Tasapelit
    //Tasapelikerroin on tasapelit * n
    //Permutaatiokerroin on n!
    //Nykyinen tavoite: Hanki kaikki permutaatiot järjestykselle 1, 2, 3.. n
    //

    long n2 = n-d; //Uusi n
    long p = 0;

    if (a+b <= n && (abs(a-b) != a+b || a+b == 0)) {
      /*for (int x = 0; x < n; x++) {
        Oikea O(n) ratkaisu tulee tähän
      }*/
      //Bruteforce test:
      //vector<long> l1 = createNumberLine(n2);
      vector<long> l2 = createNumberLine(n2);
      for (long j = 1; j <= fc(n2); j++) {
        long a1 = 0;
        long b1 = 0;
        for (long k = 0; k < (long)l2.size(); k++) {
          if (l2[k] > k+1) {
            b1++;
          } else if (l2[k] < k+1) {
            a1++;
          }
        }
        if (a1 == a && b1 == b) {
          p++;
          //cout << "\n";
          /*printArray(l1);
        printArray(l2);*/
        }
        next_permutation(l2.begin(),l2.end());
      }
        //TASAPELIT EI LASKETA OIKEIN
        //long kerroin = (d != 0) ? fcm(d)*fcm(n2) : 1;//((d%mod)*(n%mod))%mod : 1;
        //TEE STRING VERSIO MATIKASTA: 4 1 1: 576/144 = 4 = (1*2*3*->4<-)
        //cout << "Math: " << p << " * " << printFactor(n2) << " * (" << printFactor(d) << " * " << n << ") * " << "( " << printFactor(n) << " / " << printFactor(n-d) << " )" << "\n";
        //TODO: vaihda d! * JOTAIN se kerroin JOTAIN
        //(n-1) * (n-1)(n-2) d-1 kertaa ja yhteensä d kertaa
        ////(fc(n)/fc(n-d));//(( ( (p%mod) * (fcm(n)%mod) ) % mod ) * kerroin % mod ) % mod;
        //long vastaus = p * fc(n2) * (fc(d)*(n)) * sumOfSums(d, n) * fc(d);
        //kaik
        //long vastaus = p * fc(n2) * (1+2+3)  * (d*(d+1)/2);

        //long vastaus = p * fc(n2) * fc(d) * ((n-1)*(n-1+1)/2) * sumOfSums(d, n);
      long vastaus = ((p%mod) * (fcm(n2)%mod) * (sumOfSums(d, n)%mod) * (sumOfSums(d, n)%mod) * (fcm(d)%mod))%mod;
      //cout << isCorrect(vastaus, n, a, b) << "\n";//<< " | " << n << " " << a <<  " " << b << "\n";
      cout << vastaus << "\n";

    } else {
      cout << 0 << "\n";
    }
  }// else {
  //cout << 0 << "\n";
  //}
  //} 
}

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: WRONG ANSWER

Test 6

Group: 5

Verdict: WRONG ANSWER