Cod sursa(job #1081176)

Utilizator Iustin_BulimarFMI Iustin Bulimar Iustin_Bulimar Data 13 ianuarie 2014 12:14:23
Problema Frac Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.13 kb
#include <fstream>
using namespace std;
ifstream cin("frac.in");
ofstream cout("frac.out");

long long n, p, m, f[20], b[20], i, s, sgn=1;

void fact(long long n)
{
    long long d;
    for(d=2; n>1; d++)
    {
        if(n%d==0)
        {
            f[++m]=d;
            while(n%d==0 && n>1)
                n/=d;
        }
    }
}

void afis(long long k, long long n)
{
    long long i, p=1;
    for(i=1; i<=k; i++)
        p*=b[i];
    s+=sgn*(n/p);
    sgn*=-1;
}

bool cond(long long k)
{
    if(b[k-1]>=b[k])
        return 0;
    return 1;
}

void pinex(long long k, long long n)
{
    long long i;
    for(i=1; i<=m; i++)
    {
        b[k]=f[i];
        if(cond(k))
        {
            afis(k, n);
            pinex(k+1, n);
        }
    }
}
long long cauta(long long st, long long dr)
{
    long long m;
    while(st<dr)
    {
        s=0;
        m=st+(dr-st)>>1;
        pinex(1, m);
        if(m-s>=p)
            dr=m;
        else
            st=m+1;
    }
    return st;
}
int main()
{
    cin>>n>>p;
    fact(n);
    cout<<cauta(1, (1LL<<61));
    return 0;
}