找出一组数据中多次出现的所有数字（空间要求最低）

#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;}