Cod sursa(job #857006)

Utilizator srsdaniDaniel srsdani Data 17 ianuarie 2013 09:48:24
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
#include<iostream>
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
char primn[20000000];
int n,cnt;
int main()
{long i,j;
 f>>n;
 for(i=1;i<=n;i++)
    primn[i]=1;
for (i = 2; i <= n; i++)
 if (primn[i])
    {++cnt;
    for (j = i+i; j <= n; j += i)
    primn[j] = 0;}
g<<cnt;
return 1;
}