349. Intersection of Two Arrays

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.

题目含义：求两个数组的公共元素（重复多次的只记录一个）

    public int[] intersection(int[] nums1, int[] nums2) {
        Set<Integer> values = new HashSet<>();
        for (int number:nums1) values.add(number);

        Set<Integer> commons = new HashSet<>();
        for (int number:nums2)
        {
            if (values.contains(number)) commons.add(number);
        }
        int[] result = new int[commons.size()];
        Iterator<Integer> it =  commons.iterator();
        for (int i=0;i<commons.size();i++)
        {
            result[i] = it.next();
        }
        return result;     
    }