Cod sursa(job #1426991)
Utilizator | Data | 1 mai 2015 11:28:33 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.47 kb |
#include <iostream>
#include <fstream>
using namespace std;
int ciur(int n)
{
int s=1;
bool c[2000000]={};
for(short i=3;i<=n;i+=2)
{
if(c[i]==false)
{
s++;
for(int j=1;j*i<=n;j++)
c[i*j]=true;
}
}
return s;
}
int main()
{
ifstream f("ciur.in");
ofstream g("ciur.out");
int n;
f>>n;
g<<ciur(n);
f.close();
g.close();
return 0;
}