Cod sursa(job #2191637)

Utilizator WladDalwMvladutu cristian vlad WladDalwM Data 3 aprilie 2018 11:29:20
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.26 kb
Raporteaza aceasta sursa 
#include <fstream>
 using namespace std;ifstream in("fractii.in");ofstream out("fractii.out");int v[10000001];int main(){int n,i,j;long long sol=0;in>>n;for(i=2;i<=n;i++){v[i]=i-1;}for(i=2;i<=n;i++){sol+=v[i];for(j=i*2;j<=n;j+=i){v[j]-=v[i];}}out<<sol*2+1;return 0;}