public class Solution {

    /**

     * @param nums1 an integer array

     * @param nums2 an integer array

     * @return an integer array

     */

    public int[] intersection(int[] nums1, int[] nums2) {

      List<Integer> list = new ArrayList<Integer>();

        Arrays.sort(nums1);

        Arrays.sort(nums2);

        int i = 0, j = 0;

        while (i < nums1.length && j < nums2.length) {

            if(nums1[i] < nums2[j]){

                i++;

            }else if(nums1[i] == nums2[j]){

                list.add(nums1[i]);

                i++;

                j++;

            }else{

                j++;

            }

        }

        int[] inter = new int[list.size()];

        for (i = 0; i < inter.length; i++) {

            inter[i] = list.get(i);

        }

        return inter;

    }

}