IntersectionOfTwoArraysII.java

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

public class IntersectionOfTwoArraysII {
	
	public static void main(String[] args) {
		int[] nums1 = {4, 9, 5};
		int[] nums2 = {9, 4, 9, 8, 4};
		int[] ans = intersect(nums1, nums2);
		for (int i = 0; i < ans.length; i++) {
			System.out.print(ans[i] + " ");
		}
		
	}
	
	public static int[] intersect(int[] nums1, int[] nums2) {
        Arrays.sort(nums1);
        Arrays.sort(nums2);
        ArrayList<Integer> list = new ArrayList<>();
        int index1 = 0;
        int index2 = 0;
        while (index1 < nums1.length && index2 < nums2.length) {
            if (nums1[index1] == nums2[index2]) {
                list.add(nums1[index1]);
                index1++;
                index2++;
            } else if (nums1[index1] < nums2[index2]) {
                index1++;
            } else {
                index2++;
            }
        }
        int[] ans = new int[list.size()];
        for (int i = 0; i < ans.length; i++) {
            ans[i] = list.get(i);
        }
        return ans;
    }

}