Cod sursa(job #2373887)

Utilizator GhitzarinoGhita Alexandru Ghitzarino Data 7 martie 2019 15:38:53
Problema Fractii Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
#include <fstream>

using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
unsigned long long n,m,i,j,k,sol,x,p;
int s[1000005];
int main()
{
    f>>n;
    for(i=2;i<=n;i++)
        s[i]=i-1;
    for(i=2;i<=n;i++)
    {
        p+=s[i];
        for(j=i+i;j<=n;j=j+i)
            s[j]=s[j]-s[i];
    }
    g<<2*p+1;
}