Cod sursa(job #383692)
Utilizator | Data | 17 ianuarie 2010 18:03:55 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include <cstdio>
char a[2000001];
int main(){
int n;
freopen("ciur.in","rt",stdin);
freopen("ciur.out","wt",stdout);
scanf("%d",&n);
int i,j;
int ct=0;
for (i=2;i<=n;i++){
if (a[i]==0){
ct++;
for (j=2;j<=n/i;j++)
a[i*j]=1;
}
}
printf("%d",ct);
}