Cod sursa(job #2368610)

Utilizator alexandruilieAlex Ilie alexandruilie Data 5 martie 2019 16:45:29
Problema Fractii Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.26 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;ifstream f("fractii.in");ofstream g("fractii.out");int N,i,j,v[1000005];long long nr;int main(){f>>N;for(i=2;i<=N;i++)v[i]=i-1;for(i=2;i<=N/2;i++)for(j=2*i;j<=N;j+=i)v[j]-=v[i];for(i=2;i<=N;i++) nr+=v[i];g<<2*nr+1;return 0;}