Cod sursa(job #1420486)

Utilizator alex.vasiuVasiu Alexandru alex.vasiu Data 18 aprilie 2015 16:19:30
Problema Sum Scor 90
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.58 kb
#include <fstream>
#include <cstring>
#include <stdlib.h>
using namespace std;
ifstream f("sum.in");
ofstream g("sum.out");
int phi[100002],t,x;
string ch;
void phi1()
{
    int i,j;
    for (i=1; i<=100000; i++)
        phi[i]=i;
    for ( i=2; i<=100000; i++)
        if (phi[i]==i)
            for (j=i; j<=100000; j+=i)
            phi[j] =phi[j]/i*(i-1), phi[i]=i-1;
}
int main()
{
    f>>t;
    f.get();
    phi1();
    for(int i=1; i<=t; i++)
    {
        f>>ch;
        f.get();
        x=atoi(ch.c_str());
        g<<(2LL *x* phi[x])<<"\n";
    }
}