Cod sursa(job #270154)
Utilizator | Data | 3 martie 2009 19:44:00 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<stdio.h>
int v[20005];
long i,j,n,k;
int main ()
{
FILE*f=fopen("ciur.in","r");
FILE*g=fopen("ciur.out","w");
fscanf(f,"%ld",&n);
for (i=2;i<=n;i++)
if (v[i]==0)
{k++;
for (j=2*i;j<=n;j+=i)
v[j]=1;
}
fprintf(g,"%ld",k);
fclose(f);
fclose(g);
return 0;
}