Cod sursa(job #154637)
Utilizator | Data | 11 martie 2008 12:40:08 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<stdio.h>
long n,k,i,j;
char a[20001];
int main(){
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%ld",&n);
for(i=1;i<=n;i++)a[i]='0';
for(i=2;i<=n;i++)
if(a[i]=='0')
{
for(j=2*i;j<=n;j=j+i)if(j<n)a[j]='1';
k++;
}
printf("%ld",k-1);
return 0;
}