Standard 9x9 Sudoku - 146 puzzles. Three levels of difficulty. Rules of Sudoku not provided here. Select a puzzle (on-screen arrows beside Level indicator). Click on a cell to select it. Click the on-screen (or off-screen) numbers to place one in the selected cell. Duplicates will be marked in Red. Click on Zero to clear the cell. On-screen "R" to reset/re-load puzzle. Click the "pencil notes" icon in the bottom-right area of the screen to enable Manual entry of "pencil notes". Once enabled, clicking on a number will enter/clear a note. Clicking on the "pencil note" icon again will enable/disable "auto-notes" mode. In that mode all notes will be created/erased based in placed numbers only. Disabling auto "pencil notes" mode will not erase existing notes. For using advanced solving techniques on difficult puzzles, you will most likely want auto-notes disabled. To continue cell entry mode, click on the "number" icon (looks like an "8"). Feedback welcome and encouraged! Instructions for @gregatku: To witness the result of my self-solve code, set pencil-note mode to Auto. Then press "A" (for Advanced note mode). You will see an "A" in the bottom right corner. Then, at any time, press "S" and the puzzle will be solved to the limit of my self-solve code.
100% pen. All puzzles created by @gregatku. From project: https://scratch.mit.edu/projects/323229868 Reported puzzle difficulty levels are as per the author's own classes: Here are the 3 classes: Novice - no elimination strategies required Player - at least one elimination strategy needed (ones most work out for themselves after a while) Expert - needs at least 1 complex elimination strategy (ones you probably wouldn't work out by yourself). Excellent Sudoku tutorial (with a further explanation) can be found at: https://sudoku-help.com/ Notes for @gregatku Here is a description of my solving procedures (doing my best to frame them in your terms). Pressing "S" triggers an iterative loop that tries to eliminate candidates ("pencil notes") until no more are found. The loop consists two parts. 1st - a function that I refer to as "segment ownership". I'm pretty sure that's the equivalent of your "Intersect Reject". 2nd - I run a loop of two functions that I categorize as "group-of-n(1-4) owner" (n being single, pair, triple or quad). One function finding "un-hidden" groups and the other finding hidden groups. So, For n=1 I find "Unhidden" Singles ("Only Spot Boxes/Rows/Cols) and then Hidden Singles (Only Value). For n=2 I find "Unhidden" Pairs (Locked Pairs) and then Hidden Pairs (Hidden Pairs) etc. etc.
