Cod sursa(job #498272)
Utilizator | Luca Vlad llucky | Data | 4 noiembrie 2010 19:11:06 |
---|---|---|---|
Problema | Fractii | Scor | 30 |
Compilator | c | Status | done |
Runda | Arhiva de probleme | Marime | 0.37 kb |
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
long i,j,n,k,v[1000001];
FILE *f,*g;
f=fopen("fractii.in","r");
g=fopen("fractii.out","w");
k=0;
fscanf(f,"%ld",&n);
for(i=2;i<=n;i++) v[i]=i-1;
for(i=2;i<=n;i++)
{
k=k+v[i];
for(j=2*i;j<=n;j+=i) v[j] = v[j] - v[i];
}
fprintf(g,"%ld",(2*k+1));
fclose(f);
fclose(g);
return 0;
}