计算两个数的交集（一）

public class Solution {
   /**
     * @param nums1 an integer array
     * @param nums2 an integer array
     * @return an integer array
     */
    public int[] intersection(int[] nums1, int[] nums2) {
        Set<Integer> set1 = new HashSet<Integer>();
        Set<Integer> set2 = new HashSet<Integer>();
        List<Integer> list = new ArrayList<Integer>();
        for (int i = 0; i < nums1.length; i++) {
            set1.add(nums1[i]);
        }
        for (int i = 0; i < nums2.length; i++) {
            set2.add(nums2[i]);
        }
        Iterator<Integer> it = set2.iterator();
        while (it.hasNext()) {
            int num2 = it.next();
            if(set1.contains(num2)){
                list.add(num2);
            }
        }
        int[] inter = new int[list.size()];
        for (int i = 0; i < list.size(); i++) {
            inter[i] = list.get(i);
        }
        return inter;
    }
}