Cod sursa(job #2639295)
| Utilizator | Data | 1 august 2020 12:11:42 | |
|---|---|---|---|
| Problema | Fractii | Scor | 30 |
| Compilator | cpp-64 | Status | done |
| Runda | Arhiva de probleme | Marime | 0.34 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int x[1000000],n,i,j,numere;
int main()
{
fin>>n;
for(i=2;i<=n;i++)
x[i]=i-1;
for(i=2;i<=n;i++)
{numere+=x[i];
for(j=i+i;j<=n;j+=i)x[j]-=x[i];
}
fout<<numere*2+1;
return 0;
}
