UVA 10277 Boastin' Red Socks

#include<iostream>#include<cmath>#include<cstdio>#define LL long longusing namespace std;LL gcd(LL a,LL b) {return b==0?a:gcd(b,a%b);}int main(){    LL p,q;    while (scanf("%lld%lld",&p,&q)!=EOF)    {        if (p==0 && q==0) break;        if (p==0) {puts("0 2");continue;}        LL t=gcd(p,q);p/=t;q/=t;LL N;        //printf("%lld %lld\n",p,q);        for (N=2;N<=50000;N++)        {            if (N*(N-1)%q==0)          {              LL b=N*(N-1)/q*p;              double thta=sqrt((double)(4*b+1));              double ans=(1+thta)/2.0;          //    printf("%lf %lf %d\n",thta,ans,N);              if (ans-floor(ans)<1e-7)              {                  printf("%lld %lld\n",(long long)ans,(long long)(N-ans));                  break;              }          }        }        if (N>50000) puts("impossible");    }    return 0;}