Cod sursa(job #3204564)
Utilizator | Enal Gemaledin Blaugranas | Data | 17 februarie 2024 07:09:53 |
---|---|---|---|
Problema | Fractii | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.31 kb |
#include<fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int s[1000001],n,i,j;
long long r;
int main()
{
for(f>>n,i=2;i<=n;++i)
s[i]=i-1;
for(i=2;i<=n;++i)
for(r+=s[i],j=i<<1;j<=n;j+=i)
s[j]-=s[i];
g<<(r<<1)+1;
return 0;
}