Cod sursa(job #976650)
Utilizator | Data | 23 iulie 2013 16:16:38 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 60 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int N,nrp,i,j;
bool ciur[2000000];
int main()
{
fin>>N;
for(i=2;i<=N;i++)
{ if(ciur[i]==false)
nrp++;
for(j=2*i;j<=N;j+=i)
ciur[j]=true;
}
fout<<nrp;
return 0;
}