Cod sursa(job #831218)
Utilizator | Data | 8 decembrie 2012 11:56:26 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include<stdio.h>
bool v[200001];
int main(){
int n,i,j,nr=0;
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
for(i=2;i*i<=n;i++){
if(!v[i])
for(j=i*i;j<=n;j+=i)
v[j]=true;
}
for(i=2;i<=n;i++)
if(!v[i]) nr++;
printf("%d",nr);
return 0;
}