Crummy problem :( ----- (because random)

This is a permutation problem with a weak ordering requirement.

"shuffle" the grid indexes, about half the time always taking the first non-conflict from the array of empty indexes gives a valid order, if not, reshuffle till it works.
I am seeing on average slightly less than one reshuffle per grid solution over all the grids.

Processes all 361 grids in under 2 seconds total typically.

( slight cheat: All IMPOSSIBLEs are hard coded (HINT: there are very few) :)

It's not in final submit form because I wanted to test all grid sizes.

<Reveal this spoiler or all in this thread>

In reply to Re: Google Code Jam 2019 Round 1A Problem 1: Pylons by tybalt89
in thread Google Code Jam 2019 Round 1A Problem 1: Pylons by choroba

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