You're not working with 2-D coordinates ... you're working with 1-D coordinates. You're working on a line, not a plane. So, if you want to deal with finding the longest, calculate the length found.

Now, for the overlap ... it sounds like you need to do something like the following:

  1. Calculate length for each coordinate pair.
  2. Loop through the pairs, keeping each pair that provides unique coverage. If the pair's start or end coordinate is within the coverage provided by a previously-seen pair, that spot is kept by the pair with the longest coverage.
  3. Once you have determined that you're replacing pair A with pair B, you have to make sure that you're catching all pairs that are eliminated by pair B. For example, if your current list of acceptable pairs is: (1,3), (4, 6) and you come across (2,5) ... both (1,3) and (4,6) would have to be replaced with (2,5). (Assuming, of course, that I've understood your spec.)
If you want, I can help provide some code for you. /msg me if you'd like.

------
We are the carpenters and bricklayers of the Information Age.

The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.

In reply to Re: Comparing 2-D co-ordinates by dragonchild
in thread Comparing 2-D co-ordinates by aging acolyte

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