UVa 12024 - Hats

#include<bits/stdc++.h>
#define ll long long

using namespace std;

int main()
{
 ll a[13],b[13];
 int i,t,n;
 
 a[2]=1;
 a[3]=2;
 
 for(i=4; i<=12; i++)
 {
  a[i] = (i-1) * (a[i-1]+a[i-2]);
 }
 
 b[0]=1;
 
 for(i=1; i<=12; i++)
 {
  b[i]=i* b[i-1];
 }
 
 while(cin>>t)
 {
  while(t--)
  {
   cin>>n;
   cout<<a[n]<<"/"<<b[n]<<endl;
  }
 }
}