CODEWITHSUNDEEP
javaarraylistcomparesubset
CodingInCircles
CodingInCircles

Reputation: 2807

Comparing two ArrayLists - one as a subset of the other

I know that we can use the containsAll method while comparing two ArrayLists to check if one is a subset of the other. But this is what I would like. Consider an

ArrayList super = 1,2,3,4,5,6,7,8,9,10

and an

ArrayList sub1 = 1,2,3,4

and another

ArrayList sub2 = 2,4,6,8.

Now, if I did

super.containsAll(sub1), it would evaluate to true because sub1 is contained within super.

If I did super.containsAll(sub2), it would also evaluate to true because the numbers 2,4,6 and 8 are contained in super.

I would like to know if there's a way to check two ArrayLists so that super.containsAll(sub2) evaluates to false as the numbers in sub2 don't appear in the same order in super.

Upvotes: 4

Views: 3627

Answers (2)

asenovm
asenovm

Reputation: 6517

I believe you can use Collections.indexOfSublist to do that. More info here: http://docs.oracle.com/javase/6/docs/api/java/util/Collections.html

Upvotes: 7

Amir Kost
Amir Kost

Reputation: 2168

I guess you have to implement it yourself. You should traverse super, and if super(i).equals(sub2(0)), check that the next coming items are identical to those of sub2.

Upvotes: 0

Related Questions