ArrayIntersection_2.java

package com.leetcode.problems;

import java.util.Arrays;
import java.util.ArrayList;
import java.util.List;

public class ArrayIntersection_2 {
    static int[] intersect(int[] nums1, int[] nums2) {
        if (nums1 == null || nums2 == null || nums1.length == 0 || nums2.length == 0) {
            return new int[0];
        }
        int i = 0;
        int j = 0;
        Arrays.sort(nums1);
        Arrays.sort(nums2);
        List<Integer> resultList = new ArrayList<>();

        while (i < nums1.length && j < nums2.length) {
            if (nums1[i] == nums2[j]) {
                resultList.add(nums1[i]);
                i++;
                j++;
            } else if (nums1[i] < nums2[j]){
                i++;
            } else {
                j++;
            }
        }
        int[] result = new int[resultList.size()];
        for (int k = 0; k < resultList.size(); k++) {
            result[k] = resultList.get(k);
        }
        return(result);
    }
    public static void main(String[] args) {
        int[] nums1 = {1,2,2,1};
        int[] nums2 = {2,2};
        System.out.println(Arrays.toString(intersect(nums1, nums2)));
    }
}