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;}