Merging two arrayLists into a new arrayList, with no duplicates and in order, in Java

Question

I am trying to \"combine\" two arrayLists, producing a new arrayList that contains all the numbers in the two combined arrayLists, but without any duplicate elements and the

Answer 1

I'm not sure why your current code is failing (what is the Exception you get?), but I would like to point out this approach performs O(N-squared). Consider pre-sorting your input arrays (if they are not defined to be pre-sorted) and merging the sorted arrays:

http://www.algolist.net/Algorithms/Merge/Sorted_arrays

Sorting is generally O(N logN) and the merge is O(m+n).