Cod sursa(job #1929047)
Utilizator | Data | 16 martie 2017 23:44:19 | |
---|---|---|---|
Problema | Fractii | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.33 kb |
#include <fstream>
using namespace std;
ifstream f("fractii.in ");
ofstream g("fractii.out ");
int v[1000001];
int main ()
{
long long suma=0;
int n;
f>>n;
for (int i=1;i <=n;++i)
v[i]=i-1;
for (int i=2;i <=n;++i)
for (int j=2*i;j <=n;j+=i)
v[j]-=v[i];
for (int j=1;j <=n;++j)
suma+=v[j];
suma=suma*2;suma=suma+1;
g<<suma;
return 0;
}