Cod sursa(job #2266261)
Utilizator | Data | 22 octombrie 2018 15:32:45 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.36 kb |
#include <fstream>
#include <bitset>
using namespace std;
int main()
{
bitset <2000000> ciur;
int n;
ciur.set();
ciur[1]=0;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
fin>>n;
int s=0;
for(int i=2;i<=n;i++)
if(ciur[i]) {for(int j=i+i;j<=n;j+=i)
ciur[j]=0;
s++;}
fout<<s;
return 0;
}