Cod sursa(job #2368628)

Utilizator aditzu7Adrian Capraru aditzu7 Data 5 martie 2019 16:48:55
Problema Fractii Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.34 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int din[1001*1001];
long long n,i,j,ssol;
int main(){f>>n;
    for(i=1;i<=n;i++)
        din[i]=i-1;
    for(i=2;i<=n/2;i++)
    for(j=2*i;j<=n;j+=i)
    din[j]-=din[i];
    for(i=1;i<=n;i++)ssol+=din[i];
    g<<ssol*2+1<<'\n';
return 0;}