Logic Masters Deutschland e.V.

Title: XV Nurikabe VX
Type: Sudoku
Link: F-puzzles link to XV Nurikabe VX Sudoku
Link: CTC App link to XV Nurikabe VX Sudoku
Variants: Nurikabe, XV, Modified VX

1) Sudoku

• 1.1) Place the digits 0 through 8 once each in every row, column, and box.
• 1.2) When using f-puzzle, the 9 digit represents a zero. Treat the 9 as if the value is zero in all aspects of the puzzle (including mathematical operations and inequalities).
• 1.3) 36 is the secret number.

2) Nurikabe

• 2.1) The grid consists of two types of cells: water and land.
• 2.2) Water cells continuously connect adjacently with no water cell being isolated from the rest. 2X2 blocks or larger of water are NOT permitted.
• 2.3) Land forms islands of adjacently connected cells.
• a) The size of an island is determined by the largest digit in the group of cells that form the island.
• b) Digits in land cannot repeat.
• c) Islands may touch diagonally but not adjacently.

3) W and L

• 3.1) Letters outside of the grid, labeled W or L, indicate how many (W)ater or (L)and cells are in that row or column.
• 3.2) The quantity or water or land is determined by the digit adjacent to the W or L in the respective row or column.

• 4.1) An X either sums or multiplies two adjacent cells (being simultaneously a sum and a multiplication is permitted).
• a) When X acts as a sum, the two cells sum to 10.
• b) When X acts as a multiplication sign, the two cells are multiplied together with their product immediately following to the right for rows or downward for columns. Multiplications cannot have a leading zero. e.g. 4 X 8 0 3 2 is not permitted, but 4 X 5 2 0 is permitted.
• i) All sums of 10 are given.
• ii) All multiplications are given.
• 4.2) A V either sums or represents an inequality between two adjacent cells (being simultaneously a sum and an inequality is permitted).
• a) When V acts as a sum, the two cells sum to 5.
• b) When V acts as an inequality, the one cell is greater than the other in the direction of the V.
• i) All sums of 5 are given.
• ii) Not all inequalities are given.
• 4.3) X (including a product) and V cannot split water and land with the following exception: an inequality that is not on a given V may split land and water; i.e. all given X (including a product) and V are completely within water or completely within land.

Examples for Nurikabe

Examples (0 for CTC App/Penpa+, 9 for f-puzzles):
ROW 2--Six multiplied by five equals thirty (6 X 5 3 0/9).
ROW 3--Five summed with zero equals five (5 V 0/9).
ROW 4--Three summed with two equals five, also two multiplied by four equals eight (3 V 2 X 4 8).
COLUMN 1--Six is greater than five, also five is greater than three (6 V 5 V 3).
COLUMN 2--Five is greater than zero but also five summed with zero equals zero (5 V 0/9).
COLUMN 3--Two multiplied by three equals six, also six summed with four equals ten (2 X 3 6 X 4).
COLUMN 4--Seven is greater zero, also two summed with eight equals ten (7 V 0 2 X 8)