Cod sursa(job #705321)

Utilizator mihai96alexOprea Mihai Alexandru mihai96alex Data 4 martie 2012 00:56:57
Problema Ciurul lui Eratosthenes Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;
bool v[2000001];
int main()
{
    int N,i,prim,j;
    ifstream fin("ciur.in");
    ofstream fout("ciur.out");
    fin>>N;
    prim=1;
    for(i=3;i*i<=N;i+=2)
    for(j=2;j*i<N;j++)
    v[i*j]=1;
    for(i=3;i<=N;i+=2)
    if(v[i]==0) prim++;
    fout<<prim;
    fin.close(), fout.close();
}