Cod sursa(job #1978646)
Utilizator | Data | 8 mai 2017 14:22:20 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include <iostream>
#include <fstream>
#include <bitset>
using namespace std;
//ifstream f("ciur.in");
//ofstream g("ciur.out");
bitset<2000000> v;
int main()
{
int num,c,i1;
cin>>num;
c=1;
v[1]=1;
for (int i=3;i<=num;i=i+2)
{
if (v[i]==0) {i1=i+i;c=c+1;v[i]=1;
while (i1<=num){
v[i1]=1;
i1=i1+i;
}
}
}
cout<<c;
return 0;
}