Cod sursa(job #158421)

Utilizator redkar23Dezactiveazama redkar23 Data 13 martie 2008 17:18:29
Problema Ciurul lui Eratosthenes Scor 10
Compilator c Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include <stdio.h>
#define max 2000000

char v[max+1];

int main(){
long n,count=1;
FILE *f=fopen("ciur.in","r"),
     *g=fopen("ciur.out","w");
fscanf(f,"%ld",&n);

long i,j;

for(i=3;i<=n;i+=2)
   if(!v[i]) {
    count++;
    for(j=i*i;j<=n;j=j*i) v[j]=1;
   }
fprintf(g,"%ld\n",count);
fclose(g);
return 0;
}