Cod sursa(job #1234896)

Utilizator NohaiClaudiuNohai Claudiu NohaiClaudiu Data 28 septembrie 2014 12:03:35
Problema Frac Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.71 kb
#include <fstream>
 
using namespace std;
ifstream fin("frac.in");
ofstream fout("frac.out");
long long n,p,i,R,lo,mi,hi,v[2000],lg,j,sol;
int main()
{
    fin>>n>>p;
    v[1]=1;lg=1;
    for(i=2;i*i<=n;i++)
    {
        if(n%i==0)
        {
            while(n%i==0)n/=i;
            for(j=1;j<=lg;j++)
                v[j+lg]=-v[j]*i;
            lg*=2;
        }
    }
    if(n>1)
    {
        for(j=1;j<=lg;j++)
                v[j+lg]=-v[j]*n;
            lg*=2;
    }
    R=1LL;R<<=61;
    for(lo=0,hi=R;hi-lo>1;)
    {
        mi=(lo+hi)/2;
        for(sol=0,i=1;i<=lg;i++)
            sol+=mi/v[i];
        if(sol<p)lo=mi;
        else hi=mi;
    }
    fout<<hi;
    return 0;
}