Cod sursa(job #1081386)

Utilizator Iustin_BulimarFMI Iustin Bulimar Iustin_Bulimar Data 13 ianuarie 2014 16:20:10
Problema Frac Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.23 kb
#include <fstream>
using namespace std;
ifstream cin("frac.in");
ofstream cout("frac.out");

long long n, p, m, f[20], bk[20], i, s;

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 aduna(long long k, long long x)
{
    long long i, p;
    p=1;
    for(i=1; i<=k; i++)
        p*=f[bk[i]];
    if(k & 1)
        s+=x/p;
    else
        s-=x/p;
}

int pinex(long long x)
{
    long long i, k;
    k=1;
    i=1;
    s=0;
    while(k)
        if(k>m || i>m)
        {
            k--;
            i=bk[k]+1;
        }
        else
        {
            bk[k]=i;
            aduna(k, x);
            k++;
            i++;
        }
        return x-s;
}

long long cauta(long long st, long long dr)
{
    long long m, z;
    while(st<dr)
    {
        m=(st+dr)>>1;
        z=pinex(m);
        if(z>p)
            dr=m-1;
        else
            if(z==p)
                dr=m;
            else
                st=m+1;
    }
    return st;
}
int main()
{
    cin>>n>>p;
    fact(n);
    cout<<cauta(1, 1LL<<61);
    return 0;
}