Checking if 3 numbers are an arithmetic progression
Update: The question has now been unlocked. It remains closed. The Unlock is a 'probationary' act, if the situation remains in control, that's fine. If there are further problems with the question, then a permanent "historical" local may be applied.
The above question had a description, and internal test cases which were suggestive of a problem that is not what the question was actually trying to solve.
The description implied that:
- values had to be increasing (or, optionally, equal).
The reality, is that the requirements are that:
- values have to have an arithmetic progression (equal differences), (or optionally equal)
The clarification was never really clear, was posted in comments in various places, not in the question, and came after some answers were given, and before other answers were given.
The post is also very popular, and there are a lot of answers.
As far as I can tell, it's a mess, and there's no way to make everyone happy at this point.
What should be done with this question?