Cod sursa(job #2277008)
Utilizator | Data | 5 noiembrie 2018 18:24:45 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 50 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include <fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int n,i,nr,j,f[2000100];
int main(){
fin>>n;
for(i=2;i<=n;i++)
if(f[i]==0){
nr++;
for(j=2*i;j<=n;j+=i)
f[j]=1;
}
fout<<nr;
return 0;
}