[dclara]

Looks like one simple change to hashmap may not be the best answer. May I draw the conclusion from your case like that? The best score now went up to almost 3000. I couldn't imagine how many possible ways out there and one of them could be that excellent. Just curious.

[platypii]

Sorted list + binary search was 2000pts and ran much faster than the hashmap solution.

[dclara]

Thank you so much for your info. This is something I'm looking for from the beginning of the discussion.

http://www.algolist.net/Algorithms/Binary_search

This is my original answer! I should not sort the input list though since it's not necessary.

But is string.indexOf() will be even faster?