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ivanseed / google-foobar-help

Guidance on how to tackle some of the foobar challenges.
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doomsday_fuel tests #9

Closed jalepo closed 7 years ago

jalepo commented 7 years ago

Hey,

Thanks so much for the info, I'm really close on this one thanks to you folks.

Unfortunately, I'm still failing tests 3, 9 and 10.

Anyone have any further insight into what is unique about those tests?

jalepo commented 7 years ago

Never mind, I got it!

If you are inverting a matrix using the cofactors/adjugate method, be careful how you change the signs on the cofactor matrix. Just multiplying every other value by -1 will only work for matrices with odd-numbered sizes. Need to make sure that the second row starts with a negative.

On that note, it would appear that tests 3, 9 and 10 are even sized matrices greater that 2 :)

ivanseed commented 7 years ago

Glad you got it! I was thinking that they would randomize the test cases each time 🤔 .

I might write a little script that determines the input for all the tests and put them in the readme so we can see possible inputs, but not sure if Google would appreciate that.