And this is effectively a list of tuples rather than a real 2d list of non-constant dimensions.

why sort it when you can just change it to a set and then compare set values?

I'm not sure what you mean by down vote as I'm just now reading this comment. take your own advice and not take this personally is all I can say? Thanks for the response though.

seriously...? :/

I answer your question in the most informative way and you downvote me...? :o

This "horribly dying" is about your algorithm and the fact that it IS especially inefficient compared to this one. That's just a fact and a valuable information, don't take it so personally... :/

errr... this solution is the best you can do for that kind of problem... x)

for instance, your solution is horribly dying against huge inputs with huge ranges, compared to the present one. ;)

Wouldn't the time complexity of this be horrible being you're sorting a 2d array?