Cod sursa(job #1509017)

Utilizator chris998Giurgiu Cristi chris998 Data 23 octombrie 2015 13:47:19
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.45 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int taiat[20000001];
int main()
{
    int v[20000001],i,j,k=0,n;
    k=0;
    f>>n;
    for(i=1;i<=n;i++)
        v[i]=k+1;
    for(i=2;i<=n;i++)
    {
        if(taiat[i]==0)
            for(j=i+i;j<=n;j+=i)
                taiat[j]=1;
    }
    k=0;
    for(i=1;i<=n;i++)
        if(taiat[i]==0)
            k++;
    g<<k;
}