jordanbrown > RE: Kakuro next step (8/10/2022 6:39:19 AM)

I've only seen cases where I needed this level of analysis in the "very hard" puzzles. Everything below that has yielded to lesser schemes, where you look only at one row (or column) and the columns (or rows) that intersect it. Just eliminating marking only those options that are possible in both horizontal and vertical gets you a lot. Then look for "this row needs a 3, and only one of these squares can provide a 3". Look for "None of these squares has a 6, so the combinations that require a 6 are not possible". Then "this row (or column) has two squares with {2,7}, so one of them must be a 2 and the other must be a 7, and no other square can have either a 2 or a 7". (Similarly for combinations of three numbers.) And similar patterns. The biggest secret is painstaking attention to detail. After the initial flurry of filling stuff in, I start walking across every single row and every single column, looking at all of the numbers and seeing how they relate to one another and to the possible options for that row or column. And every time I make a change, even one as small as removing the mark for a single value as not possible, that means that I have to reanalyze the crossing rows or columns.



