hdu 1099 Lottery

#include<stdio.h>
__int64 gcd(__int64 a,__int64 b)
{
return b==0?a:gcd(b,a%b);
}
int main()
{
int i,j,prime[]={2,3,5,7,11,13,17,19},n,t;
__int64 s1,s2,m,d,gd;
while(scanf("%d",&n)==1)
{
s2=1;s1=0;t=0;
if(n==21 || n==22)
{
for(i=2;i<21;i++) s2*=i;d=s2/n;
for(i=1;i<=n;i++)
{
s1+=s2/i;
while(s1>d)
{
s1-=d;t++;
}
}
gd=gcd(d,s1);s1/=gd;s2=d/gd;
}
else
{
for(i=2;i<n;i++) s2*=i;
for(i=1;i<=n;i++) s1+=n*s2/i;
t=s1/s2;s1%=s2;
gd=gcd(s2,s1);s1/=gd;s2/=gd;
}
m=t;
if(s1==0)
{
printf("%d\n",t);continue;
}
while(m/=10) printf(" ");
printf("  %I64d\n",s1);
printf("%d ",t);
m=s2;
while(m/=10) printf("-");
printf("-\n");
m=t;
while(m/=10) printf(" ");
printf("  %I64d\n",s2);
}
return 0;
}