Cod sursa(job #2256079)

Utilizator georgitTreista Georgiana georgit Data 7 octombrie 2018 22:00:02
Problema Principiul includerii si excluderii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.23 kb
#include <fstream>
#define MAX 2000000

using namespace std;

bool prim[MAX+5];
int k,nrprim[MAX+5];
long long v[MAX+5];
void CIUR()
{
    for(int i=2;i<=MAX;i++)
        if(!prim[i])
        {
            nrprim[++k]=i;
            for(int j=2*i;j<=MAX;j+=i)
                prim[j]=1;
        }
}
int main()
{
    ifstream f("pinex.in");
    ofstream g("pinex.out");
    int Q;
    f>>Q;
    CIUR();
    for(int q=1;q<=Q;q++)
    {
        long long a,b;
        int n=0;
        f>>a>>b;
        for(int i=1;nrprim[i]*nrprim[i]<=b;i++)
        {
            if(b%nrprim[i]==0)
            {
                while(b%nrprim[i]==0)
                    b/=nrprim[i];
                v[++n]=nrprim[i];
            }
        }
        if(b>1)
            v[++n]=b;
        long long card=a;
        int maxi=(1<<n);
        for(int i=1;i<maxi;i++)
        {
            long long p=1,m=0;
            for(int j=0;j<n;j++)
                if((1<<j)&i)
                {
                    m++;
                    p=p*v[j+1];
                }
            if(m%2==0)
                card=card+a/p;
            else
                card=card-a/p;
        }
        g<<card<<"\n";
    }
    return 0;
}