TriMill / ctcdiy

Click here to open the interface. A list of example puzzles is available here.

About

CTCDIY is an online sudoku application inspired by Cracking the Cryptic's application. Unlike theirs, however, CTCDIY allows you to upload your own puzzles as JSON files. Some examples are available with the link above, and more will be added as more features are released. Currently, there is support for NxN square boards, irregular sudokus, killer sudokus, and kropki sudokus (and any modification that doesn't require new additions to the grid, eg. knight's move).

Using the website

Puzzles can be loaded either from a URL or from a local file. The file format is described below. Once the puzzle is loaded you can begin playing. Controls are shown on the right side of the screen.

• Click a cell to select it. Ctrl+click, Shift+click, or drag to select multiple cells.
• Use the arrow keys to move the selected cell.
• Use the number keys 1to 9 to enter digits.
• Use the number keys with Ctrl to enter center pencilmarks.
• Use the number keys with Shift to enter corner pencilmarks.
• Use the number keys with Alt to highlight cells.
• Use Backspace, Delete, or Space to clear a cell.
• Use Alt with Backspace, Delete, or Space to remove highlighting.

Puzzle format

Puzzles are stored as JSON. The only required field is board, the rest are optional. | Name | Type | Description | | board | Array of two integers (width and height) or string (either "sudoku" or "plain" ) | Specifies the dimensions of the board. Both "sudoku" and "plain" create a 9x9 board, "sudoku" additionally adds darker lines to create the 3x3 boxes. | | title | String | Shown at the top of the page | | description | String | Shown below the puzzle | | givens | Array of integers, length at most width * height | Place unchangeable digits into the puzzle. | | decorations | Array of objects (see below) | Add decorations to the puzzle (eg. borders, cages, highlighting) |

Decorations

Any combination of decorations can be applied to a puzzle. Decorations have no function. Each decoration is an object with the field type specifying the object's type. Each decoration is used in at least one puzzle (linked above) | Type | Other fields | Description | | sudoku_grid | None | Draws darker borders around the 3x3 cells. Used internally with "board": "sudoku" | | border | path | Draws darker borders along a custom path. The elements of path are positions of grid intersections | | killercage | path, value (optional) | Draws a killer sudoku cage. The elements of path contain two fields: pos, a grid intersection position, and offset, a direction. value represents the sum of the cage and is drawn at the first element of path. | | kropki | pos, color (optional) | Draws a Kropki dot. To line it up between two cells, one coordinate of pos should end with a .5, the other should be whole. color defaults to white if not provided. |

Types

• Position: an array of length 2 representing an [x, y] pair. Top-left is [0,0], increasing right and down. Depending on usage, this may refer to a cell or to a gridline intersection.
• Direction: a value describing a direction, one of c (center), n, s, e, w (cardinal directions), nw, ne, sw, se (diagonals)