Cod sursa(job #353763)
Utilizator | Data | 5 octombrie 2009 23:33:57 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.38 kb |
#include <stdio.h>
int n, cnt,i,j;
bool prim[2000005];
int main(void)
{
freopen("ciur.in", "r", stdin);
freopen("ciur.out", "w", stdout);
scanf("%d", &n);
for(i=2;i<=n;++i)
prim[i]=1;
for(i=2;i<=n;++i)
if (prim[i])
{
++cnt;
for(j=i+i;j<=n;j+=i)
prim[j]=0;
}
printf("%d\n", cnt);
return 0;
}