PDF

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

This is a “Franken-Friday” puzzle variation.

Theme: This is not all white!

Rules: Standard Masyu rules. Also, some white circles must be shaded in to become black circles to allow solution of the puzzle.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 6:00, Master = 9:00, Expert = 18:00

Solution: PDF

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)

Theme: Logical theme you may encounter when solving

Rules: Standard Masyu rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 0:50, Master = 1:15, Expert = 2:30

Solution: PDF

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)

Theme: Mostly themeless? A mostly straight-forward puzzle to start the week.

Rules: Standard Masyu rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

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

Solution: PDF

Fifth in a series with puzzle solving tips. This time, with some advice on global constraints that arise in loop puzzles.

Some of you have asked why I don’t put “general tips” up before I post any puzzles. I find that learning how to solve puzzles is more interesting than reading how to do every single step. I won’t post a list of the top 20 Slitherlink patterns you should memorize, for example, on the rules and info page. Most of you would probably get more enjoyment figuring those out for yourself. But, after you’ve solved a challenge, I do like highlighting some of the things as constructor I tried to include, perhaps as a lesson for the future. This is what I will do this week with parity constraints for the Friday Masyu.

(more…)

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)

Theme: Almost Twisted! – Slightly imperfect, but more difficult as a result.

Rules: Standard Masyu rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standard: Masyu Master = 2:00, Expert = 6:00, Novice = 20:00

Note: Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #5”

Solution: PDF and solving video.

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)

Theme: Smiley Face – our first (but probably not last) use of this theme here.

Rules: Standard Masyu rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standard: Masyu Master = 1:00, Expert = 3:00, Novice = 10:00

Solution: PDF

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)

Theme: Our 25th prescription! Enjoy this easy Masyu puzzle.

Rules: Standard Masyu rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standard: Masyu Master = 0:30, Expert = 1:30, Novice = 5:00

Solution: PDF