Union and Intersection of sorted array

union.java

import java.io.*;
import java.util.*;

class unionIntersection
{
    public static void main (String[] args) throws java.lang.Exception
    {
        unionIntersection obj = new unionIntersection();
        obj.approachTwo();
    }
    
    public void approachTwo()
    {
        int[] a = new int[]{1, 3, 5, 6 ,7, 9, 10, 12};
        int[] b = new int[]{1, 2, 4, 5, 6};
        
        List<Integer> union = new ArrayList<Integer>();
        List<Integer> inter = new ArrayList<Integer>();
        
        int i = 0, j = 0, lengtha = a.length, lengthb = b.length;
        
        while((i < lengtha) && (j < lengthb)) {
            
            if(a[i] == b[j]) {
                inter.add(a[i]);
                union.add(a[i]);
                i++;
                j++;
                continue;
            }
            if( a[i] > b[j]) {
                union.add(b[j]);
                j++;
            } else {
                union.add(a[i]);
                i++;
            }
        }
        
        while(i < lengtha) {
            union.add(a[i]);
            i++;
        }
        
        while(j < lengthb) {
            union.add(b[j]);
            j++;
        }
        
        System.out.println(" Union ");
        for(Integer x: union) {
            System.out.println(x);
        }
        
        System.out.println(" Intersection ");
        for(Integer x: inter) {
            System.out.println(x);
        }
    }
}