Cod sursa(job #209316)

Utilizator ditiBilescu Adrian diti Data 21 septembrie 2008 19:55:29
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
#include<stdio.h>
#define dim 1000000

long i,n,j,c;

FILE*f=fopen("ciur.in","r"),*g=fopen("ciur.out","w");

int main()
{
char a[dim];

	fscanf(f,"%ld",&n);
	for(i=1;i<=n;i++)
	 a[i]='1';

 for(i=2;i<=n;i++)
  if(a[i]=='1')
   {c++;
   for(j=i+i;j<=n;j+=i)
	a[j]='0';

   }

  fprintf(g,"%ld",c);

return 0;
}