POJ 2244 Eeny Meeny Moo

#include <cstdio>
#include <cmath>
#include <cstring>
#include <string>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <stack>
#include <map>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <utility>
using namespace std;

#define rep(i,j,k) for (int i=j;i<=k;i++)
#define Rrep(i,j,k) for (int i=j;i>=k;i--)

#define Clean(x,y) memset(x,y,sizeof(x))
#define LL long long
#define ULL unsigned long long
#define inf 0x7fffffff
#define mod %100000007
int n;

int ans[200];

int getans( int n , int k )
{
int pos = 0;
rep(i,2,n)
pos = ( pos + k ) % i;
return pos + 1;
}

int main()
{
Clean(ans,-1);

while( scanf("%d",&n) == 1 )
{
if ( !n ) break;
n--;
if ( ans
!= -1 )
{
printf("%d\n",ans
);
break;
}
for(int i = 2;;i++)
if ( getans(n,i) == 1 )
{
ans
= i;
printf("%d\n",ans
);
break;
}
}
return 0;
}