Roller Coaster by Serkan Yürekli

Roller Coaster by Serkan Yürekli


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

Theme: 1 to 9 (for patron Veep, who co-wrote this style for the 2016 MIT Mystery Hunt)

Author/Opus: This is the 130th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Fill each cell with a digit from 1 to 9 (1 to 6 in example) so that no digit repeats in any row or column, and also draw a single, non-intersecting loop through some of the cells in the grid. The loop cannot pass through gray cells. Numbers on the outside of the grid show the sum of digits of ALL horizontal/vertical loop segments in that row/column in order. (Note: as in column 5 of the example, only segments that pass horizontally/vertically in a row/column appear as clues; the 5 in that column is not part of a vertical segment and is not represented by a clue). Not all outside clues are given, and unclued rows/columns can have any possible distribution of loop segments/sums.

Roller Cosaster Example by Serkan Yürekli

Answer String: Enter the digits in the 1st row from left to right, followed by a comma, followed by the 6th row from left to right.

Time Standards (highlight to view): Grandmaster = 9:15, Master = 14:00, Expert = 28:00

Solution: PDF; a solution video is available here.

Note: Follow this link for other less common Number Placement puzzles.

  • egrieg says:

    Very nice puzzle with a lot of interesting deductions. Very creative to combine loop and latin square types 🙂

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