Cod sursa(job #1610523)

Utilizator ASTELOTudor Enescu ASTELO Data 23 februarie 2016 16:53:39
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.38 kb
Raporteaza aceasta sursa 
#include<cstdio>
char ciur[2000001];
int i,j,n,m,p=2,up=1414;
int main ()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
while(p<=up)
    {
    for(i=2;i*p<=2000000;i++)
        ciur[i*p]=1;
    p++;
    while(ciur[p]==1)
        p++;
    }
int nr=0;
for(i=2;i<=n;i++)
    if(ciur[i]==0)
        nr++;
printf("%d",nr);
return 0;
}