Cod sursa(job #2231178)

Utilizator andreistanStan Andrei andreistan Data 13 august 2018 13:08:25
Problema Sum Scor 95
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.55 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("sum.in");
ofstream g("sum.out");

int Euler[100001];

void precalc(int N)
{
    for(int i = 2; i <= N; i++)
        Euler[i] = i;
    for(int i = 2; i <= N; i++)
        if(Euler[i] == i)
            for(int j = i; j <= N; j += i)
                Euler[j] = Euler[j] / i * (i - 1);
}

int main()
{
    int N;
    precalc(100000);
    f >> N;
    while(N--)
    {
        int x;
        f >> x;
        g << 2LL * Euler[x] * x << '\n';
    }
    return 0;
}