Cod sursa(job #1418030)
Utilizator | Data | 11 aprilie 2015 18:59:46 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.37 kb |
#include <fstream>
#include <iostream>
#include <bitset>
using namespace std;
ifstream f ("ciur.in");
ofstream o ("ciur.out");
int main() {
int i,ii,j,x;
bitset<2000001>a;
f>>x;
j=0;
for (i=2;i<x;i++)
{
if(a[i]!=1)
{
j++;
for(ii=i+i;ii<x;ii=ii+i)
{
a[ii]=1;
}
}
}
o<<j;
o.close();
f.close();
return 0;
}