Cod sursa(job #3220506)
Utilizator | flavius flvcrs | Data | 3 aprilie 2024 20:51:31 |
---|---|---|---|
Problema | Fractii | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.53 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
long long v[1000001];
int main()
{
long long n=1000000;
for(int i=1;i<=n;i++)
v[i]=i;
for(int i=2;i<=n;i++)
{
if(v[i]==i)
{
for(int j=i;j<=n;j+=i)
{
v[j]=v[j]*(i-1)/i;
}
}
}
long long s=0;
f>>n;
for(int i=2;i<=n;i++)
s+=v[i];
s=s*2+1;
g<<s;
return 0;
}