Cod sursa(job #611811)

Utilizator Luncasu_VictorVictor Luncasu Luncasu_Victor Data 3 septembrie 2011 15:57:52
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include <fstream>
std::ifstream f("ciur.in");
std::ofstream g("ciur.out");
bool p[2000001];

void prime(){
    int i=2,j;
    while(i<=1414){
        while(p[i])i++;
        for(j=i*i;j<=2000000;j+=i)p[j]=true; i++;};
}

int main(){
    int n,i,x=0;
    f>>n;
    prime();
    for(i=2;i<=n;i++)if(!p[i])x++;
    g<<x;
}