Cod sursa(job #388868)
Utilizator | Tanase Alexandru tase | Data | 31 ianuarie 2010 11:35:49 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<stdio.h>
int n, nr=0,i,j;
char ciur[2000001];
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
for(i=2;i<=n;++i)
if(ciur[i]==0)
{
nr++;
ciur[i]=1;
for(j=i*2;j<=n;j=j+i)
ciur[j]=1;
}
printf("%d",nr);
return 0;
}