Given two arrays, write a function to compute their intersection.

Example:
Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2].

Note:

• Each element in the result must be unique.
• The result can be in any order.

这道题我用了2个for，不过其实我发现只要一个也能做，先存进去，然后第二个再放，放不进去就是重复的。

public class Solution {
    public int[] intersection(int[] nums1, int[] nums2) {
        HashSet<Integer> set = new HashSet();
        for(int i=0;i<nums1.length;i++){
            for(int j=0;j<nums2.length;j++){
                if(nums1[i] == nums2[j]){
                    set.add(nums1[i]);
                }
            }
        }
        int[] arr = toInt(set);
        return arr;
    }
    public int[] toInt(Set<Integer> set) {
        int[] a = new int[set.size()];
        int i = 0;
        for (Integer val : set) a[i++] = val;
        return a;
    }
}