PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s on edges)

Theme: Double Trouble

Author/Opus: This is the 4th puzzle from guest contributor David Altizio.

Rules: Form a single non-intersecting loop. Clues inside the grid represent the number of neighboring cells visited by the loop; if there is more than one number in a cell, each number should be represented with a separate loop segment. There is no 2×2 rule of Tapa in this puzzle.

See also this example:

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:30, Expert = 3:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for other Tapa-Like Loop puzzles. More Tapa-Like Loop puzzles can be found in the Tapa-Like Loop Collection by Prasanna Seshadri.

PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s on edges)

Theme: Focal Point

Author/Opus: This is the 343rd puzzle from our managing editor Serkan Yürekli.

Rules: Form a single non-intersecting loop. Clues inside the grid represent the number of neighboring cells visited by the loop; if there is more than one number in a cell, each number should be represented with a separate loop segment. There is no 2×2 rule of Tapa in this puzzle.

See also this example:

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:15, Expert = 2:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for other Tapa-Like Loop puzzles. More Tapa-Like Loop puzzles can be found in the Tapa-Like Loop Collection by Prasanna Seshadri.

Our past week with Kuromasu and Snake Pit puzzles is collected in this PDF and the solutions are in this PDF.

The daily solution videos are on the posts and linked below:

This next week will feature Tapa-Like Loop puzzles. Also, we have added Penpa solving links to old posts for every Snake Pit, Kuromasu, and Tapa-Like Loop puzzle recently. You can see all the fully digitized genres on our Penpa Notes page.

As an extra bonus for this week, I’m sharing a YouTube link to a recent puzzle constructors panel that Prasanna Seshadri and I were part of for the World Sudoku + Puzzle Convention. If you are interested in different stories about how we got into puzzle construction, things we keep in mind when writing puzzles, even knowing who some of our favorite constructors are, please check out the video.

Tied to this event, I’ve been wondering if there are other kinds of videos (besides solving videos) to add to our YouTube channel. If you think an “Ask Dr. Sudoku” vlog, construction or competition stories, or anything else might be interesting for our open Monday slots, we may try to make them in 2022.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a number entry mode.)

Theme: Noughts and Crosses

Author/Opus: This is the 29th puzzle from guest contributor Joseph Howard.

Rules: Divide the grid along the boundary lines so that every cell belongs to a snake. A snake is a one-cell-wide path at least two cells long that does not touch itself, not even diagonally. Circled cells must be at one of the ends of a snake. A snake may contain one circled cell, two circled cells, or no circled cells at all. Numbered cells must be part of a snake with a length of exactly that number of cells. A snake may contain one number, multiple identical numbers, or no numbers at all. Two snakes of the same length cannot touch each other horizontally or vertically. Cells with an X cannot be an end of a snake.

Also see this example:

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 9:30, Master = 14:00, Expert = 28:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for more Snake Pit puzzles. Follow these links for other Fillomino or Snake puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: X

Author/Opus: This is the 14th puzzle from guest contributor Swaroop Guggilam.

Rules: Shade some empty cells black so that each number indicates the total count of white cells connected vertically and horizontally to that number including the numbered cell itself. Black cells cannot share an edge, and all white cells must belong to a single connected group.

Also see this example:

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 8:00, Expert = 16:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for more Kuromasu puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Even/Odd

Author/Opus: This is the 3rd puzzle from guest contributor Eric Fox.

Rules: Shade some empty cells black so that each number indicates the total count of white cells connected vertically and horizontally to that number including the numbered cell itself. Black cells cannot share an edge, and all white cells must belong to a single connected group.

Also see this example:

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:00, Master = 7:00, Expert = 14:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for more Kuromasu puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a number entry mode.)

Theme: Twins

Author/Opus: This is the 210th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Divide the grid along the boundary lines so that every cell belongs to a snake. A snake is a one-cell-wide path at least two cells long that does not touch itself, not even diagonally. Circled cells must be at one of the ends of a snake. A snake may contain one circled cell, two circled cells, or no circled cells at all. Numbered cells must be part of a snake with a length of exactly that number of cells. A snake may contain one number, multiple identical numbers, or no numbers at all. Two snakes of the same length cannot touch each other horizontally or vertically. Cells with an X cannot be an end of a snake.

Also see this example:

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:45, Expert = 7:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for more Snake Pit puzzles. Follow these links for other Fillomino or Snake puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a number entry mode.)

Theme: Diamonds

Author/Opus: This is the 342nd puzzle from our managing editor Serkan Yürekli.

Rules: Divide the grid along the boundary lines so that every cell belongs to a snake. A snake is a one-cell-wide path at least two cells long that does not touch itself, not even diagonally. Circled cells must be at one of the ends of a snake. A snake may contain one circled cell, two circled cells, or no circled cells at all. Numbered cells must be part of a snake with a length of exactly that number of cells. A snake may contain one number, multiple identical numbers, or no numbers at all. Two snakes of the same length cannot touch each other horizontally or vertically.

Also see this example:

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 4:00, Expert = 8:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for more Snake Pit puzzles. Follow these links for other Fillomino or Snake puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Symmetric House

Author/Opus: This is the 35th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Shade some empty cells black so that each number indicates the total count of white cells connected vertically and horizontally to that number including the numbered cell itself. Black cells cannot share an edge, and all white cells must belong to a single connected group.

Also see this example:

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:15, Expert = 2:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for more Kuromasu puzzles.

If you missed our post last weekend, our latest e-book, Star Battle 2 by JinHoo Ahn and Murat Can Tonta, is now available for sale in our store and two more Masterpiece Sudoku Mixes are on track to be added before the end of the month.

This week is also the World Sudoku + Puzzle Convention and our contributing puzzlemasters Prasanna Seshadri and Ashish Kumar constructed some of the puzzles alongside other international authors. Please check out some of the puzzle rounds and other events. I will be speaking as part of a “Puzzle Authors panel” on Thursday the 18th from 14:30-16:00 GMT. I don’t know if I will be able to find time to “compete” during the official schedule due to my current commitments — the extended time for next weekend may help — but I wish those that do compete the best of luck and skill and hope to see many of you in the future at the next live WSPC.

Our past week with a variety mix from guest authors is collected in this PDF and the solutions are in this PDF.

The daily solution videos are on the posts and linked below:

This next week will feature two Region Division styles, with a set of three Kuromasu puzzles and three Snake Pit puzzles.