The last Loop/Path puzzle is one of the “new” styles that debuted in the Breadth of America loop variety round, a Cross Border Parity Loop by Craig Kasper. (We expect this puzzle to be much harder for those who didn’t solve the three competition puzzles that preceded it.)
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; use tab to alternate to a shading mode to mark the loop states)
Author/Opus: This is the 9th puzzle from guest contributor Craig Kasper.
Rules: Draw a single, non-intersecting loop that has two states, which are white and black. The puzzle grid has heavily shaded borders, which define areas in the grid. Whenever the loop crosses a border (including borders inside an area), it changes state from white to black or from black to white. A black circled clue provides the number of cells in each area that the loop traverses in the black state, and a white circled clue provides the number of cells in each area that the loop traverses in the white state. Each “?” represents an unknown integer, zero or larger.
See also this example:
Estimated Difficulty: 2.5-3 stars
Solution: PDF for all Loop/Path playoff puzzles.
Note: Follow this link for other uncommon Loop/Path puzzles.