Cod sursa(job #837700)
Utilizator | Data | 18 decembrie 2012 15:18:21 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.27 kb |
#include <fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
char a[2000001];
int n,j,nr,i;
int main () {
in>>n;nr=0;
for(i=2;i<=n;i++)
if(a[i]==0){
nr++;
for(j=2*i;j<=n;j=j+i)
a[j]=1;
}
out<<nr;
return 0;}