Cod sursa(job #1013283)
Utilizator | Data | 20 octombrie 2013 18:52:24 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.44 kb |
#include <iostream>
#include <fstream>
#include <bitset>
using namespace std;
bitset <2000001> b;
int main()
{
b[1]=1;
long n,i,j;
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
i=2;
while(i*i<=n)
{ j=2*i;
while(j<=n)
{
b[j]=1;
j=j+i;
}
i++;
}
g<<n-b.count();
f.close();
g.close();
return 0;
}