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;
}

stack<long> createNumberStack(int n) {
  stack<long> answer = {};
  for (long i = 1; i <= n; i++) {
    answer.push(i);
  }
  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);
  }
}

long sumOfSums(int d, int n) {
  return (fcm(n)%mod)/((fcm(d)%mod)*(fcm(n-d)%mod));
}

//Current iteration = a+b, koska tasapelejä ei lasketa.
long iterateGame(stack<long> nl, long a, long b, long a1, long b1) {
  long i = a1+b1 != 0 ? a1+b1 : 1;
  long p = 0;
  int size = (int)nl.size();
  for (int j = 0; j < size; j++) {
    long num = nl.top();
    bool work = true;
    nl.pop();
    if (i > num) {
      a1++;
    } else if (i < num) {
      b1++;
    } else { //Tasapeli, ei mahdollista.
      work = false;
    }
    if (a1 > a || b1 > b) {
      work = false;
    } else if (size == 1) {
      return 1;
    }
    if (work) {
      p += iterateGame(nl, a, b, a1, b1);
    }
  }
  return p;
}

int main() {
  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

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

    if (a+b <= n && (abs(a-b) != a+b || a+b == 0)) {
      stack<long> l1 = createNumberStack(n2);
      p = iterateGame(l1, a, b, 0, 0);
      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";
    }
  }
}

Test 1

Group: 1, 2, 3, 4, 5

Verdict: WRONG ANSWER

Test 2

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

Test 3

Group: 3, 4, 5

Verdict: WRONG ANSWER

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