Cod sursa(job #566091)
Utilizator | Data | 28 martie 2011 17:21:51 | |
---|---|---|---|
Problema | Fractii | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.28 kb |
#include<fstream.h>
long double s[1000009],sum=0,i,j,n;
int main()
{ifstream f("fractii.in");
ofstream h("fractii.out");
f>>n;
for(i=1;i<=n;i++)
s[i]=i-1;
for(i=2;i<=n;i++)
for(j=i+i;j<=n;j+=i)
s[j]=s[j]-s[i];
for(i=1;i<=n;i++)
sum=sum+s[i];
sum=2*sum+1;
h<<sum;
return 0;}