Cod sursa(job #2302639)
Utilizator | Data | 14 decembrie 2018 22:21:38 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include <fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int main(){
int n,i,j,l=0;
bool x[2000003];
fin >> n;
for(i=2;i<=n;i++) x[i]=true;
for(i=2;i<=n;i++)
if(x[i]){ l++;
for(j=i;j<=n;j+=i) x[j]=false;
}
fout << l;
return 0;
}