剑指offer 数组中只出现一次的数字

利用HashSet

import java.util.*;
public class Solution {
    public void FindNumsAppearOnce(int [] array,int num1[] , int num2[]) {
        Set<Integer> set = new HashSet<Integer>();
        for (int i = 0; i < array.length; i++) {
            if (!set.contains(array[i])) set.add(array[i]);
            else set.remove(array[i]);
        }
        //取值方法1
        int k = 0;
        for (Integer i : set) {
            if(k++ == 0)    num1[0] = i;
            else num2[0] = i;
        }
        //取值方法2
        Integer [] in = new Integer [2];
        set.toArray(in);
        num1[0] = in[0];
        num2[0] = in[1];
    }
}