PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: 2 and 3

Author/Opus: This is the 387th puzzle from our managing editor Serkan Yürekli.

Rules: Locate some automobiles in the grid having size 1×2 or 1×3. Each number in the grid should be part of an automobile, indicating the number of unoccupied cells the automobile can move to by traveling along its longest axis, stopped only by an edge of the grid or another automobile. No more than one number can be in an automobile. (Unlike other variations of this puzzle, there are no extra automobiles without numbers here.)

Also, see this example:

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:00, Master = 8:00, Expert = 16:00

Solution: PDF and solving video.

Note: Follow this link for more Parking Lot puzzles.

Since 2021, we have posted some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This eleventh Sunday Stumper of 2022 is a Parking Lot (Hex) puzzle by Murat Can Tonta. Can you pack in all the automobiles (using the empty center and other open space wherever necessary)? Note that we’ve referred to this style before as “Tren”; while not a common puzzle style, we are updating to the nomenclature “Parking Lot” for this stumper.

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: Empty Center

Author/Opus: This is the 234th puzzle from contributing puzzlemaster Murat Can Tonta.

Rules: Locate some automobiles in the grid having size 1×2 or 1×3. Each number in the grid should be part of an automobile, indicating the number of unoccupied cells the automobile can move to by traveling along its longest axis, stopped only by an edge of the grid or another automobile. (Unlike other variations of this puzzle, there are no extra automobiles without numbers here.)

Also, see this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 21:00, Master = 30:00, Expert = 60:00

Solution: PDF and solving video.

Note: Follow this link for more Parking Lot puzzles.

Note that we’ve referred to this style before as “Tren” and this particular variation as “Ghost Tren”. While not a common puzzle style, we are updating to the nomenclature “Parking Lot” for “Tren” and “Parking Lot (Extra Parking)” for “Ghost Tren” for this style this week.

PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: Prime Edges

Author/Opus: This is the 380th puzzle from our managing editor Serkan Yürekli.

Rules: Locate some automobiles in the grid having size 1×2 or 1×3. Each number in the grid should be part of an automobile, indicating the number of unoccupied cells the automobile can move to by traveling along its longest axis, stopped only by an edge of the grid or another automobile. No more than one number can be in an automobile; automobiles can also be placed without any numbers, with no restrictions on their ability to move. All unused cells must be part of a single connected group.

Also, see this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 12:30, Master = 20:00, Expert = 40:00

Solution: PDF and solving video.

Note: Follow this link for more Parking Lot puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools).

Theme: 11V

Author/Opus: This is the 6th puzzle from guest contributor Elyot Grant.

Rules: Shade some cells so that the numbers outside the grid indicate the groups of consecutive black cells which are in that row/column in order, either from left to right or from top to bottom. There must be at least one white cell between any consecutive shaded groups. Rows and columns without outside clues can have any pattern of shaded and unshaded cells. Also, all the shaded cells must be able to be split into the eleven given pentomino shapes. Pentominoes may be flipped and/or rotated.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 3:15, Master = 4:45, Expert = 9:30

Solution: PDF and solving video.

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

PDF

or solve online (using our beta test of Penpa-Edit tools).

Theme: 11X

Author/Opus: This is the 5th puzzle from guest contributor Elyot Grant.

Rules: Shade some cells so that the numbers outside the grid indicate the groups of consecutive black cells which are in that row/column in order, either from left to right or from top to bottom. There must be at least one white cell between any consecutive shaded groups. Rows and columns without outside clues can have any pattern of shaded and unshaded cells. Also, all the shaded cells must be able to be split into the eleven given pentomino shapes. Pentominoes may be flipped and/or rotated.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 4:15, Expert = 8:30

Solution: PDF and solving video.

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

PDF

or solve online (using our beta test of Penpa-Edit tools).

Theme: 7-L

Author/Opus: This is the 4th puzzle from guest contributor Elyot Grant.

Rules: Shade some cells so that the numbers outside the grid indicate the groups of consecutive black cells which are in that row/column in order, either from left to right or from top to bottom. There must be at least one white cell between any consecutive shaded groups. Rows and columns without outside clues can have any pattern of shaded and unshaded cells. Also, all the shaded cells must be able to be split into the seven given pentomino shapes. Pentominoes may be flipped and/or rotated.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 1:00, Master = 2:00, Expert = 4:00

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

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

PDF

or solve online (using our beta test of Penpa-Edit tools; click on a cell to cycle between a white circle, a black circle, and an empty cell).

Theme: Logical

Author/Opus: This is the 23rd puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Fill some cells with either a single white or black “stone” so that there is exactly one black stone in each row and column. Digits on the outside indicate the count of stones in that row/column up to and including the black stone.

See also this example:

Answer String: Enter the contents of the 4th row from left to right, followed by a comma, followed by the 6th row from left to right. Use a capital B for a black stone, a capital W for a white stone, and a capital X for a blank cell.

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

Solution: PDF

This week we are sharing easy sample puzzles from our ebook The Puzzlemasters’ Workshop which showcases six authors exploring new puzzle styles or variations with 8-10 challenges in each section. Today’s post is Ghost Tren.

PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: Clue Symmetry and Logic

Background: Variation of the object placement/object movement puzzle Tren, with new rules that allow for unclued “ghost” blocks and require overall connectivity of white cells. This specific variation with both new rules was originally created by Murat Can Tonta in 2012 but explored much more fully here as an extension of the original Tren.

Rules: Locate some train cars in the grid having size 1×2 or 1×3. Each number in the grid should be part of a car, indicating the number of unoccupied cells the car can move to by traveling along its longest axis. No more than one number can be in a train car; cars can also be placed without any numbers, with no restrictions on their ability to move. All unused cells must be part of a single connected group.

Example by Thomas Snyder:

(No official times or solution entry for this week; just click “SOLVE?” when finished.)

Solution: Last page of PDF

Note: More Ghost Tren puzzles can be found in The Puzzlemasters’ Workshop.

(view directly for a larger image)

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: Logical

Author/Opus: This is the 3rd puzzle from guest contributor Yuki Kawabe.

Rules: Combination of Sundoko, Snake, and Shape puzzle styles.

Sundoko: Shade some cells to make sunglasses, consisting of a bridge (a given line, in red) and two lenses made out of orthogonally connected cells that are symmetric with respect to the perpendicular bisector of the bridge. Two lenses may not share an edge, but can intersect at a point. Cells with the bridges are not shaded, except at the bridge ends. Numbers in the grid are unshaded, and indicate the total count of unshaded cells connected vertically and horizontally to the numbered cell, including the cell itself.
Sundoko example:

Snake: Shade some cells to create a one-cell wide snake in the grid that does not cross or touch itself, not even diagonally. The snake starts and ends at the black circles and must pass through all white circles.
Snake example:

Shape: Place each of the given shapes into the grid exactly once (rotations and reflections allowed). Shapes cannot touch each other, not even diagonally.
Shape example:

SSS: In SSS, shade some cells to make sunglasses, create a single snake, and place all of the shapes in the grid. Shaded cells of different categories (sunglasses, snake, shapes) cannot share an edge. Number clues referring to unshaded cell counts consider all three categories of objects as shaded cells in this hybrid.

Or see this example:

Answer String: Enter the length in cells of each of the shaded segments (sunglasses, snake, and shapes) from left to right for the marked rows, starting at the top. Separate each row’s entry from the next with a comma.

Time Standards (highlight to view): Grandmaster = 16:00, Master = 22:00, Expert = 44:00

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

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: Logical

Author/Opus: This is the 2nd puzzle from guest contributor Yuki Kawabe.

Rules: Combination of Sundoko, Snake, and Shape puzzle styles.

Sundoko: Shade some cells to make sunglasses, consisting of a bridge (a given line, in red) and two lenses made out of orthogonally connected cells that are symmetric with respect to the perpendicular bisector of the bridge. Two lenses may not share an edge, but can intersect at a point. Cells with the bridges are not shaded, except at the bridge ends. Numbers in the grid are unshaded, and indicate the total count of unshaded cells connected vertically and horizontally to the numbered cell, including the cell itself.
Sundoko example:

Snake: Shade some cells to create a one-cell wide snake in the grid that does not cross or touch itself, not even diagonally. The snake starts and ends at the black circles and must pass through all white circles.
Snake example:

Shape: Place each of the given shapes into the grid exactly once (rotations and reflections allowed). Shapes cannot touch each other, not even diagonally.
Shape example:

SSS: In SSS, shade some cells to make sunglasses, create a single snake, and place all of the shapes in the grid. Shaded cells of different categories (sunglasses, snake, shapes) cannot share an edge. Number clues referring to unshaded cell counts consider all three categories of objects as shaded cells in this hybrid.

Or see this example:

Answer String: Enter the length in cells of each of the shaded segments (sunglasses, snake, and shapes) from left to right for the marked rows, starting at the top. Separate each row’s entry from the next with a comma.

Time Standards (highlight to view): Grandmaster = 3:45, Master = 5:15, Expert = 10:30

Solution: PDF