Domino test case duplicate stones about rust HOT 4 CLOSED

wouldn't it be OK if we were using two domino sets though? see no reason why the dominoes would have to be unique

from rust.

I am just trying to understand the rules of this "game". I have not really played this kind of loop "chain" dominos. I'd like to add more test cases to a Swift version I am working on. My first impression is that all stones in a chain should be unique because most games with dominos are played using one one set of unique dominos. Otherwise we can have test cases like (1,1), (1,1), (1,1), (1,1), (1,1), that would be valid but don't really make sense. Plus I'd like to expand my version to check to see if a stone can be inserted into a valid chain or if a stone can be removed and still have a valid chain etc.

from rust.

Well, let's explain why those tests cases are there in the first place, they stop some incorrect solutions from falsely declaring a chain is possible when it isn't.

Consider the [(1, 2), (2, 1), (3, 4), (4, 3)] test case. Some solutions will falsely declare that a chain can be made of [(1, 2), (2, 1)] when this is incorrect because it hasn't used all the dominoes. Sure, it could be changed to [(1, 2), (2, 3), (1, 3), (4, 5), (5, 6), (4, 6)], but that seems unnecessary.

Similarly, [(1, 2), (2, 3), (3, 1), (2, 4), (2, 4)] is there to stop some solutions from falsely declaring that (1, 2), (2, 3), (3, 1) is a valid chain when it's clearly invalid because it hasn't used all the dominoes. Sure, it could be changed into [(1, 2), (2, 3), (3, 1), (2, 4), (4, 5), (5, 2)] but it also seems unnecessary.

Why did I say in both cases that something seems unnecessary? Becuase it over-complicates the test cases to expose simple problems. I think it should be a principle to find the simplest test case that exposes a problem.

I have no opinions about [(1, 2), (5, 3), (3, 1), (1, 2), (2, 4), (1, 6), (2, 3), (3, 4), (5, 6)] though. That was here long before my time.

Plus I'd like to expand my version to check to see if a stone can be inserted into a valid chain or if a stone can be removed and still have a valid chain etc.

You may find that those checks devolve into "is that domino of the form (x, x)?"

If the checks can affect multiple dominoes, then the checks become "are the dominoes themselves a valid chain?"

from rust.

I see, is more about making it a little more challenging.

from rust.