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.

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.

PDF

or solve online (using our beta test of Penpa-Edit tools using a composite mode where left click inside cell shades square, left click + drag draws line segment, right click inside cell adds dot, and right click on cell edge adds an x.)

Theme: Clue Symmetry and Logic

Rules: Locate some blocks in the grid, either 1×2 or 1×3 in size, with each block containing one of the given numbers. Each block is allowed to move in its long direction, stopped only by an edge of the grid or another block. A block’s number must indicate the total possible movement of the block. Or see here.

Answer String: Enter the size of consecutive groups of cells that belong to blocks in each marked row from left to right, separating each row’s entry with a comma (ie “151,22,44,22”).

Time Standards (highlight to view): Grandmaster = 3:15, Master = 5:30, Expert = 11:00

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools using a composite mode where left click inside cell shades square, left click + drag draws line segment, right click inside cell adds dot, and right click on cell edge adds an x.)

Theme: Railroad Crossing (“Tren” means train in Turkish.)

Rules: Locate some blocks in the grid, either 1×2 or 1×3 in size, with each block containing one of the given numbers. A block’s number must indicate the total possible movement of the block along either direction in its long direction, where it is blocked only by an edge of the grid or another block. Or see here.

Answer String: Enter the size of consecutive groups of cells that belong to blocks in each marked row from left to right, separating each row with a comma (ie 151,22,44,22).

Time Standards (highlight to view): Grandmaster = 5:00, Master = 7:30, Expert = 15:00

Solution: PDF