Cross+A Sudoku

Sudoku (also known as "Number Place") is a placement puzzle. The puzzle is most frequently a 9 x 9 grid made up of 3 x 3 subgrids (called "regions"). Some cells already contain numbers, known as "givens". The goal is to fill in the empty cells, one number in each, so that each column, row, and region contains the numbers 1 through 9 exactly once. Each number in the solution therefore occurs only once in each of three "directions", hence the "single numbers" implied by the puzzle's name.

Cross+A can solve and create many kinds of sudokus.

• Sudoku X
• Argyle Sudoku
• Jigsaw
• Godoku
• Asterisk
• Girandola
• Center Dot
• Windoku
• Sudoku-DG
• Anti-Knight Sudoku
• Anti Diagonal Sudoku
• Killer Sudoku
• Greater Than Sudoku
• Even-Odd Sudoku
• Consecutive Sudoku
• Kropki Sudoku
• Sukaku
• Chain Sudoku
• Frame Sudoku
• 10 x 10, 12 x 12, 15 x 15, 16 x 16
• Samurai Sudoku
• Flower Sudoku
• Sohei Sudoku
• Kazaguruma
• Butterfly Sudoku
• Cross Sudoku
• Gattai-3
• Twodoku
• Triple Doku
• Twin Corresponding Sudoku
• Hoshi
• Star Sudoku
• Tridoku

In some sudokus main diagonals also contain the digits 1 through 9. This variant is called "Sudoku X" or "Diagonal Sudoku". Use the check box Diagonals for such sudokus.

"Argyle Sudoku" contains additional diagonals; every marked diagonal line contains each digit not more than once. The argyle pattern is derived from the tartan of Clan Campbell, in eastern Scotland.

Also the puzzle may contain the regions of random (irregular) shape; this variant is called "Jigsaw", "Geometry Sudoku" ("Geometry Number Place"), "Irregular Sudoku" or "Kikagaku Nanpure".

"Godoku" (also known as "Wordoku") is similar to sudoku, but uses letters instead of numbers. Once the grid is complete, the hidden word may be revealed.

In "Asterisk Sudoku" there is an additional area, shown on the grid by shading nine specially selected cells. Those nine cells must also contain 1 to 9.

"Girandola" is an ordinary sudoku with one extra group of cells. This group must also contain digits 1 through 9. (Girandola is a kind of revolving firework.)

"Center Dot" is a variant of sudoku, where central cells of each region form an extra region. This region must contain digits 1 through 9.

Sudoku may contain additional four regions 3 x 3. This format was first introduced in the Dutch newspaper "NRC Handelsblad" by Peter Ritmeester. It is called "Windoku" ("Four-Box Sudoku", "Hyper Sudoku").

"Sudoku-DG" (also known as "Offset Sudoku") contains 9 disjoint groups in the puzzle, one for each relative box position. Each group has a distinct color. The group of 9 cells with the same color must also contain digits 1 through 9.

In "Anti-Knight Sudoku" all cells at a chess knight move (at a distance of 2 by 1) must hold different numbers.

In "Anti Diagonal Sudoku" each diagonal has at most three different digits.

In "Killer Sudoku", sub-regions have specified sums, and no number can be repeated within a region. This variant also called "Sums Sudoku" ("Sums Number Place").

"Greater Than Sudoku" is the variation of the original sudoku. In addition, greater than or less than signs (">" or "<") in the walls indicate that one cell's number is greater than or less than an adjacent cell's number. Also called "Compdoku".

"Even-Odd Sudoku": fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. White cells must contain odd digits, gray cells must contain even digits.

In "Consecutive Sudoku" (or "1-away Disallowed Number Place"), all the places where orthogonally adjacent cells are consecutive numbers have been specially marked.

"Kropki Sudoku" (the Polish word "kropki" means "dots"; also known as "Dots Sudoku") is the variation of the original sudoku. If absolute difference between two digits in neighboring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighboring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.

In "Sukaku" ("Suuji Kakure"; also known as "Pencilmark Sudoku") has 81 groups of digits in a 9 x 9 grid. Like a standard sudoku, the puzzle must be completed in such a way that each row, each column and each 3 x 3 box contains digits 1 through 9. Only the candidates shown in the grid can be used.

"Chain Sudoku" (also known as "Strimko") consists of a group of circles arranged in a square grid and containing given clues in various places. The object is to fill all empty circles so that the digits appear exactly once in each row, column and chain.

The program can solve and create puzzles from 4 x 4 to 9 x 9.

"Frame Sudoku" (also known as "Outside Sum Sudoku") consists of an empty grid. Numbers in the outside frame equal the sum of the first three numbers in the corresponding row or column in the given direction.

The program can solve puzzles with various sizes of grid: 10 x 10 (the subgrids' size is 5 x 2), 12 x 12 (the subgrids' size is 4 x 3), 15 x 15 (the subgrids' size is 5 x 3), 16 x 16 (the subgrids' size is 4 x 4).

Gattai is a Japanese word meaning merged or fused; this term is used for overlapping sudoku. A number after the word "Gattai" indicates how many 9 x 9 sudokus are in the puzzle ("Gattai-3", "Gattai-4", "Gattai-5", etc.).

"Samurai Sudoku" ("Gattai-5") is one of the sudoku variation with overlapping sudoku grids. The puzzle consists of five grids, one in the center and the other 4 overlapping each corner grid of the central one. This means that the numbers must be placed correctly for all the five puzzle squares.

"Flower Sudoku" has five sudoku puzzles in layout, similar to Samurai Sudoku. However, these puzzles overlap each other much more than in Samurai. The center grid is fully covered by the remaining four sub-puzzles.

Named for the warrior monks of medieval Japan, "Sohei Sudoku" has four merged grids. Each grid has two overlapping areas.

"Kazaguruma" ("Windmill Sudoku") consists of five grids, one in the center and the other 4 overlapping the central one. This means that the numbers must be placed correctly for all the five puzzle squares.

"Butterfly Sudoku" is the variation of the original sudoku. The puzzle consists of four grids 9 x 9. The numbers must be placed correctly for all the four puzzle squares.

"Cross Sudoku" has five merged grids. The numbers must be placed correctly for all the five puzzle squares.

"Gattai-3" consists of three grids 9 x 9.

"Twodoku" (also known as "Sensei Sudoku", "DoubleDoku") consists of two grids 9 x 9. The numbers must be placed correctly for both puzzle squares.

The program can solve Twodoku which contains the regions of irregular shape:

"Triple Doku" consists of three grids 9 x 9. The numbers must be placed correctly for all puzzle squares.

"Twin Corresponding Sudoku" consists of a pair of standard sudoku puzzles each with some starting digits. To get a complete solution for the twin puzzles, it is necessary to solve each twin puzzle, but the complete solution of the twin puzzles will be obtained by substituting the corresponding values of the digits from one twin sudoku into the other.

"Hoshi" consists of six large triangles; the numbers 1 through 9 must be placed into the triangular cells of each large triangle. Every line (of any length, even uncontinous) contains every digit not more than once.

In "Star Sudoku" the row on the outer edge of the grid includes the cell on the nearest sharp end of the figure.

"Tridoku" was invented by Japheth Light (USA). The puzzle consists of nine large triangles; the numbers 1 through 9 must be placed into the triangular cells of each large triangle. Also, the numbers 1 through 9 must be placed in the three legs of the inner shaded triangle and in the three legs of the outer shaded triangle. No two neighboring cells may contain the same number.