Karnaugh Map Solver

Give this the cells where your function is 1, and the cells you do not care about if you have them, and it draws the Karnaugh map in Gray code order and groups it for you. The answer comes back as the minimal sum of products with every group shown on the map and listed as a product term, alongside the minimal product of sums found by solving the zeros and applying De Morgan. Don't care cells are handled properly: each one is swallowed into a group only when that makes the group bigger, and the output names the ones that were used. Groups are found by Quine-McCluskey and then an exhaustive search over the prime implicants, so the result is the smallest expression and not merely a small one.