Cod sursa(job #705324)

Utilizator mihai96alexOprea Mihai Alexandru mihai96alex Data 4 martie 2012 01:03:04
Problema Ciurul lui Eratosthenes Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include<stdio.h>
using namespace std;
bool v[2000001];
int main()
{
    int N,i,prim,j;
    freopen("ciur.in","r",stdin);
    freopen("ciur.out","w",stdout);
    scanf("%d",&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++;
    printf("%d",prim);
}