Archive for the ‘Other Shading’ Category:

Yajisan Kazusan (No 2×2) by Jamie Hargrove

Yajisan Kazusan by Jamie Hargrove

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Theme: No 2×2 White Blocks

Author/Opus: This is the 5th puzzle from guest contributor Jamie Hargrove.

Rules: Shade some cells black so that all unshaded number and arrow clues indicate the exact count of shaded cells in the given direction. Shaded cells cannot share an edge, and all white cells must remain connected as part of a single contiguous group. It is allowed to shade over some of the numbered cells; a shaded over clue may or may not be true. Also, as an extra rule from standard Yajisan Kazusan, there cannot be any fully unshaded 2×2 cell blocks in the grid.

Answer String: For each row from top to bottom, enter the number of shaded cells as a single string.

Time Standards (highlight to view): Grandmaster = 5:00, Master = 12:00, Expert = 24:00

Note: Follow this link for other less common Shading puzzles.

Yajisan Kazusan by Jamie Hargrove

Yajisan Kazusan by Jamie Hargrove

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Theme: 2×2 Clue Blocks

Author/Opus: This is the 3rd puzzle from guest contributor Jamie Hargrove.

Rules: Shade some cells black so that all unshaded number and arrow clues indicate the exact count of shaded cells in the given direction. Shaded cells cannot share an edge, and all white cells must remain connected as part of a single contiguous group. It is allowed to shade over some of the numbered cells; a shaded over clue may or may not be true.

Also, see this example:

Yajisan Kazusan by Thomas Snyder

Answer String: For each row from top to bottom, enter the number of shaded cells as a single string. For the example, the answer is “20212”.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 5:15, Expert = 10:30

Note: Follow this link for other less common Shading puzzles.

Birthday Surprise Puzzle by Prasanna Seshadri

(Note: This bonus puzzle is at a Saturday+ difficulty, and is being posted today to mark the occasion of Prasanna’s birthday.)

Birthday Surprise by Prasanna Seshadri

(View image directly for larger form.)

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Theme: 26 on 03/02

Author/Opus: This is the 152nd puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: This puzzle combines Yajisan-Kazusan with Tapa with additional rules.

Left grid = Yajisan-Kazusan (No 2×2): Shade some cells black so that all unshaded number and arrow clues indicate the exact count of shaded cells in the given direction (all counts extend through gaps in the grid). Shaded cells cannot share an edge, and all white cells must remain connected as part of a single contiguous group. It is allowed to shade over some of the numbered cells; a shaded over clue may or may not be true. Also, no 2×2 area inside the grid can be fully white.

Right grid = Tapa: Shade some empty cells black to create a single connected wall. Numbers in a cell indicate the length of consecutive shaded blocks in the neighboring cells. If there is more than one number in a cell, then there must be at least one white (unshaded) cell between the black cell groups. Cells with numbers cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid.

Additional rule 1: Clues in the middle of the grids indicate the sum or the difference of the number of shaded cells in that row between the grids (possibly both).

Additional rule 2: The shading of the green outlined regions is equivalent in the two grids in the shared cells (if the cell labeled “A” in the illustration below is shaded in one grid it must be shaded in both grids). Note that the 3 and 2 share all locations except for the bottom vertical stem of the numbers which is shifted.

Answer String: For each marked row, enter the length in cells of each of the unshaded segments from left to right in the Yajisan-Kazusan followed by the length of each of the shaded segments from left to right in the Tapa. Separate each row’s entry from the next with a comma (but do not use commas in between the Yajisan-Kazusan and Tapa entry parts in a given row). Enter both digits for any two-digit large segment in an entry.

Time Standards (highlight to view): Grandmaster = 30:00, Master = 1:00:00, Expert = 2:00:00

Yajisan Kazusan by Murat Can Tonta

Yajisan Kazusan by Murat Can Tonta

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Theme: No Obvious Lies (for Jamie Hargrove)

Author/Opus: This is the 53rd puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Shade some cells black so that all unshaded number and arrow clues indicate the exact count of shaded cells in the given direction. Shaded cells cannot share an edge, and all white cells must remain connected as part of a single contiguous group. It is allowed to shade over some of the numbered cells; a shaded over clue may or may not be true.

Also, see this example:

Yajisan Kazusan by Thomas Snyder

Answer String: For each row from top to bottom, enter the number of shaded cells as a single string. For the example, the answer is “20212”.

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:15, Expert = 6:30

Note: Follow this link for other less common Shading puzzles.

Sunday Surprise: 100th Puzzle Spectacular by Prasanna Seshadri

100th Puzzle Spectacular by Prasanna Seshadri

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(After solving the puzzle (or before, if you desire) look at this additional image for another challenge.)

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Theme: Clue Symmetry and Logic

Author/Opus: This is the 100th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: This puzzle combines styles that involve shading cells. All rules are standard for the given puzzle types (Tapa, Light and Shadow, Nurikabe, Kurotto, and Cave) which appear in the indicated spots of the grid (see below).

Tapa: Shade some empty cells black to create a single connected wall. Numbers in a cell indicate the length of consecutive shaded blocks in the neighboring cells. If there is more than one number in a cell, then there must be at least one white (unshaded) cell between the black cell groups. Cells with numbers cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid.

Light and Shadow: Divide the grid into shaded and unshaded regions, each containing exactly one number and with an area equal to that number. Numbers in white cells are part of white regions; numbers in shaded cells are part of shaded regions. Same colored regions cannot share an edge.

Nurikabe: Shade some empty cells black so that the grid is divided into white areas, each containing exactly one number and with the same area in cells as that number. Two white areas may only touch diagonally. All black cells must be connected with each other, but no 2×2 group of cells can be entirely shaded black.

Kurotto: Shade some cells so that each circled number represents the total count of shaded cells in connected groups sharing an edge with that number. Cells with circles cannot be shaded.

Cave: (The inside of the cave with the numbered cells is shaded here!) Shade some cells to form a single connected group — the cave — with no enclosed, unshaded cells. In other words, all unshaded cells must be connected by other unshaded cells to an edge of the grid. All numbered cells must be a part of the cave, with each number indicating the total count of cells connected vertically and horizontally to the numbered cell including the cell itself.

Additionally, there are two diamonds made out of cells in each grid. Each cell in the smaller diamond corresponds to two cells in the same position in the larger diamond (see example below). The corresponding cells must differ in their shading (i.e., if a cell in the smaller diamond is shaded, both corresponding cells in the larger diamond are unshaded; if a cell in the smaller diamond is unshaded, both corresponding cells in the larger diamond are shaded).

Answer String: Enter the answer to the additional challenge in ALL CAPITAL LETTERS (no spaces)

Time Standards (highlight to view): Grandmaster = 25:00, Master = 32:30, Expert = 1:05:00

This is a Melon puzzle. (19 – Pento Coral)

Pento Coral by Palmer Mebane

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Theme: “Hard” Practice (this was a WPC puzzle style) — in contrast to this post.

Rules: Place each of the 11 pentominoes into the grid exactly once, with rotations and reflections allowed, to form a valid “Coral”. In a Coral puzzle, all blackened areas are connected, but no group of 2×2 cells is entirely blackened. Also, there are no unshaded areas enclosed by the coral (meaning each unshaded cell must have a path through its edges with other unshaded cells to a border). Numbers outside the grid indicate the lengths of groups of shaded cells in that row/column, but not necessarily in order.

Or see this example from the 22nd WPC instruction booklet.

Answer String: Enter the identities of the pentominoes (one capital letter for each, even if in multiple cells) appearing in the marked rows from left to right (eg “ILN,WVXT”).

Time Standards (highlight to view): Grandmaster = 10:00, Master = 20:00, Expert = 40:00

The Puzzle Robot #20 – Graffiti

Graffiti by Serkan Yürekli

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Theme: Clue Symmetry and Logic

Rules: Blacken some cells and then draw a single non-intersecting loop through all remaining white cells. Outside clues indicate the size of all groups of blackened cells in that row or column in order. There must be at least one white cell between each of these groups. When no clues are given, any number of cells may be shaded in that row/column. Or see here.

Answer String: For each marked column, enter the length in cells of the longest vertical segment. Enter 0 if there are no vertical segments. Enter these values as a single string (eg “230124”).

Time Standards (highlight to view): Grandmaster = 4:15, Master = 7:30, Expert = 15:00