Delete_The _Selected_Prime

#include <iostream>
#include <cmath>
#define N 99999

using namespace std;

bool flag[N];

void prime()
{
    for (int i = 2; i < N; i++)
    {
        if (i % 2 == 0)
        {
            flag[i] = false;
        }
        else
        {
            flag[i] = true;
        }
    }
    for (int i = 3; i < sqrt(N); i+= 2)
    {
        if (flag[i])
        {
            for (int j = i + i; j < N; j+= i)
            {
                flag[j] = false;
            }
        }
    }

    for (int i = 2; i < 100; i++)
    {
        if (flag[i])
        {
            cout << i << endl;
        }
    }
}

int main()
{
    prime();
    return 0;
}