Cod sursa(job #2710062)

Utilizator adelinaheroiuAdelina Heroiu adelinaheroiu Data 21 februarie 2021 19:09:36
Problema Fractii Scor 0
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.33 kb
Raporteaza aceasta sursa 
#include <fstream>

using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int i,j,n,x,nr,fi[1000001];
int main()
{f>>n;nr=0;
fi[1]=1;
for(i=1;i<=n;++i)
    fi[i]=i;
for(i=2;i<=n;++i)
    if(fi[i]==i)
{fi[i]--;
for(j=2;j*i<n;++j)
    fi[j*i]=fi[j*i]/i*(i-1);
nr=nr+fi[i];
}
g<<nr*2-1;
    return 0;
}