Cod sursa(job #334473)
Utilizator | Data | 26 iulie 2009 21:46:59 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include<stdio.h>
#define N 2000005
char p[N];
int main(){
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
int i,j,n;
long nr=0;
scanf("%d",&n);
for (i = 2; i <= n; i ++)
if (p[i] == 0) {
nr++;
for (j = i + i; j <= n; j += i)
p[j] = 1;
}
printf("%ld\n\n\n",nr);
return 0;
}