Picnic

Timeout answer

#include <stdio.h>
#include <vector>

using namespace std;
int sub(vector<int> v, int N);

int c, n, m;
int in[50][2];
int ans;

int main ()
{
    int i,j;
    int tmp;

    // C = number of test case
    scanf("%d", &c);
    //printf("%d\n", c);

    for (i=0; i<c; i++) {
        // n = number of student
        // m = number of pair
        scanf("%d %d", &n, &m);
        //printf("n = %d, m = %d\n", n,m);
        for (j=0; j<m; j++) {
            // in = array of pair
            scanf("%d %d", &in[j][0], &in[j][1]);

            if (in[j][0] > in[j][1])    {
                tmp = in[j][1];
                in[j][1] = in[j][0];
                in[j][0] = tmp;
            }
            
            // in[][0] < in[][1] is always TRUE
            //printf("(%d, %d) ", in[j][0], in[j][1]);
            
        }

  vector<int> v;
  ans = 0;
  sub(v, n);
        //printf("\n");

  printf("%d", ans);

  if (i < c-1) printf("\n");
    }
}





int sub(vector<int> v, int N)
{
 if (v.size() == N)
 {
  // Check in-set duplication
  int ii=0;
  while (ii<N) {
   if(v.at(ii)>=v.at(ii+1)) return 0;
   ii+=2;
  }

  // Check inter-set duplication
  ii=0;
  while (ii+2<N) {
   if(v.at(ii)>=v.at(ii+2)) return 0;
   ii+=2;
  }

  // All duplication removed
  // Print the set
  /*
  ii=0;
  while (ii<N) {
   if (ii%2==0) printf(" (");
   printf("%d ", v.at(ii));
   if (ii%2==1) printf(")");
   ii++;
  }
  printf("\n");
  */

  // compare "in" and "current set"
  bool bGood = false;
  ii=0;
  while (ii<N)
  {
   for(int goodFriends=0; goodFriends<m; goodFriends++)
   {
    if(v.at(ii)==in[goodFriends][0] && v.at(ii+1)==in[goodFriends][1])
    {
     bGood = true;
     break;
    }
   }
   if (bGood == false)
    break;
   else
   {
    if (ii < N-2) {
     bGood = false;
    }
    ii+=2;
   }
  }
  
  if (bGood)
  {
   //printf("ok\n");
   ans++;
  }
  else
  {
   //printf("not ok\n");
  }

  return 0;
 }

 for (int an=0; an<N; an++)
 {
  bool duplicated = false;

  for (int ii=0; ii<v.size(); ii++)
  {
   if(v.at(ii) == an) { duplicated = true; break; }
  }
  
  if (duplicated == false)
  {
   v.push_back(an);
   sub(v, N);
   v.pop_back();
  }
 }
}