Greg's SUDOKU - Must Click Green Flag to start, then Select a Puzzle using [<] [<<] [>>] [>] (FB & FF -/+10). [Reset] to set the grid with the chosen puzzle. [Random] to pick a random Puzzle. [N],[P],[E] for a random Novice, Player, Expert Puzzle. [Check] to highlight any incorrectly placed numbers. Click a grid cell to choose a number for it. [#] or # key to pick the number (0 or space to clear it). If you Click more than 1 cell before picking a number then they will all be set to the value you choose. [L] to toggle display of the Puzzle List summaries. [/] to see options in empty cells (pencil marks) - NEW!, but this is not available for [N]ovice puzzles as this would make most of them trivial. For [P]layer & [E]xpert puzzles when you click it, the options remain visible unless you turn it off (or start a new puzzle) and are automatically updated as you go. NOTE: Best played in the Project Page where the clones forming the grid's cells cannot be accidentally moved when you click on them. Full screen is okay but the Pencil Marks [/] are not rendered nearly as well so Normal size is recommended. Alternatively, turn the Pencil Marks [/] on in Normal Screen mode and then switch to Full screen. BTW - It is touch screen compatible! And for the benefit of those of you who have never solved a Sudoku puzzle before here are the rules: You have to fill the entire 81 cell grid with the numbers 1-9. But you have to do it in a certain way, so that each of the 9 Rows, each of the 9 Columns and each of the 9 3x3 Boxes has each of the 9 numbers from 1-9 in it, once and only once each. So no Row, Column or 3x3 Box is allowed to have the same number twice. The numbers already placed in the grid at the start, are enough information for you to be able to find the one and only solution to the puzzle, by logical deduction. Sometimes that's really easy to do, and sometimes it's really difficult, depending on the particular puzzle. You should never guess a number! That will inevitably lead to you putting the wrong number in the wrong spot and then you won't be able to solve it. You can always use the [Check] button to find which, if any, numbers you got wrong (they will be highlighted in Red). But it really should be called the [Cheat] button!
Created by @gregatku for use in Coding Classes for Kids Unlimited, for whom I work as a Coding teacher. Inspired by a comment in the Scratch Design Studio "Puzzled", suggesting there should be a Sudoku puzzle there. I wondered why the hell I hadn't built a Sudoku project in Scratch before, after all I handcrafted every Sudoku Puzzle that appeared in a now defunct Aussie Newspaper from 2006-2013. So here it is. My Sudoku puzzles are not like anybody else's because they are not computer generated. Furthermore I don't believe in the Easy, Medium or Hard way of classifying Sudoku puzzles, I do it in a much more meaningful way, here are my 3 classes: [N]ovice - no elimination strategies required [P]layer - at least one elimination strategy needed (ones most work out for themselves after a while) [E]xpert - needs at least 1 complex elimination strategy (ones you probably wouldn't work out by yourself) However I have some Player puzzles that are actually harder to solve than some Expert ones, and some Novice puzzles that are harder to solve than some Player ones. So I also assign a mathematically calculated difficulty Rating, where the higher the value the more difficult the puzzle is to solve. What's more as an added bonus in most of them you will find the mathematically calculated difficulty Rating actually visible in the puzzle itself as given values. The calculation is in part based on the difficulty of spotting the particular solving Rules required to solve the puzzle. Speaking of solving Rules, I also have my own unique (and I believe more meaningful) names for many of the well known solving Rules. My sudoku-help.com Website explains all the Classification, difficulty Rating and solving Rules spoken about above, much more fully than I have room to do here. It also has 3 very helpful Tutorials on how to solve Sudoku puzzles, including a full pictorial explanation of how to solve Expert puzzle No. 10. By the way my Expert puzzles are really difficult. Of course in this game I do make them all very much easier for you to solve, because you can always click the [Check] button to get any incorrectly placed numbers highlighted. But that's kind of cheating! When originally Shared this project had a limited number of puzzles built into it, but this number will grow gradually over time, such that I plan to eventually have at least a few hundred puzzles (currently there's 146), uploaded. Hope you have as much fun playing it as I did coding it. Regards Greg
