Cod sursa(job #203621)
Utilizator | Data | 17 august 2008 23:53:54 | |
---|---|---|---|
Problema | Fractii | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.44 kb |
#include <stdio.h>
int No[1000000];
int main ()
{
FILE *in, *out;
in=fopen("fractii.in", "r");
out=fopen("fractii.out", "w");
long n, i, j, k, NrPrime=0, TOT;
scanf("%ld", &n);
No[1]=1;
for(i=2; i<=n; i++)
{
TOT=i;
for(j=2*i; j<=n; j+=i)
No[j]=1;
for(k=2; k<=i; k++)
if(!No[k]&&i%k==0)
TOT*=(k-1), TOT/=k;
NrPrime+=TOT;
}
printf("%ld\n", NrPrime*2+1);
fclose(in);
fclose(out);
return 0;
}