CODEWITHSUNDEEP
javaarraylistmultidimensional-arrayintersection
Taha Körkem
Taha Körkem

Reputation: 906

Intersection of Two Dimensional ArrayList in Java

I want to intersection list1, list2 and list3 in a ArrayList. So, I want to intersection ArrayLists of arrayList2D. arrayList2D can contain (max) six ArrayList. How I can do?

That's intersection of two Lists.

public <T> List<T> intersection(List<T> list1, List<T> list2) {
    List<T> list = new ArrayList<T>();

    for (T t : list1) {
        if(list2.contains(t)) {
            list.add(t);
        }
    }

    return list;
}

That's my codes

    ArrayList<ArrayList<Integer>> arrayList2D=new ArrayList<ArrayList<Integer>>();

    ArrayList<Integer> list1 = new ArrayList<Integer>();
    list1.add(0);
    list1.add(8);
    list1.add(15);
    list1.add(26);
    list1.add(124);
    ArrayList<Integer> list2 = new ArrayList<Integer>();
    list2.add(0);
    list2.add(7);
    list2.add(17);
    list2.add(26);
    list2.add(178);
    ArrayList<Integer> list3 = new ArrayList<Integer>();
    list3.add(4);
    list3.add(8);
    list3.add(12);
    list3.add(26);
    list3.add(128);

    arrayList2D.add(list1);
    arrayList2D.add(list2);
    arrayList2D.add(list3);

Upvotes: 1

Views: 733

Answers (1)

Jekin Kalariya
Jekin Kalariya

Reputation: 3507

Ok so as per my understanding you need to intersect all arraylists contain under arrayList2D.

public <T> List<T> intersection(List<T> list1, List<T> list2) {
    list1.retainAll(list2);
    return list1;
}

make other method which you need to call

public static List<Integer> getAllIntersection(ArrayList<ArrayList<Integer>> arrayList2D) {
    List<Integer> finalList = arrayList2D.get(0);
    for (int i=1; i<arrayList2D.size(); i++) {
        finalList=intersection(finalList,arrayList2D.get(i));
    }
    System.out.println("firstList"+finalList);
    return finalList;
}

then finaly call getAllIntersection(arrayList2D) to get desire result

Upvotes: 1

Related Questions