#include <iostream>
#include <bitset>
#include <map>
using namespace std;
void CheckDuplicates(int *array, int len)
{
    bitset<40000> bt1;
    bitset<40000> bt2;
    for (int i = 0; i < len; i++)
    {
        if (bt1.test(array[i]) == 0)
        {
            bt1.set(array[i]);
        }
        else
        {
            bt2.set(array[i]);
        }
    }
    //打印。
    for (int i = 0; i < 40000; i++)
    {
        if (bt2.test(i) == 1)
        {
            cout << i << " ";
        }
    }
    cout << endl;
}
int main()
{
    int a[] = {1,1,3,4,5,6,6,7,8,8,9,6,5,5,54,3,2,44,0};
    CheckDuplicates(a,sizeof(a)/sizeof(int));
    return 0;
}