or solve online (using our beta test of Penpa-Edit tools; use the tab key to alternate between shading and number entry modes)
Theme: Fives (originally on the US round for the 2016 WPF Puzzle Grand Prix)
Author/Opus: This is the 240th puzzle from Thomas Snyder, aka Dr. Sudoku.
Rules: Variation of Nanro.
Label some cells with numbers to form a single connected group of labeled cells. No 2×2 group of cells may be fully labeled. Each number must be equal to the total count of labeled cells in that bold region, and all bold regions contain at least one labeled cell. The given numbers indicate how many cells are labeled in that region (but not necessarily which cells are labeled). When two numbers are orthogonally adjacent across a region boundary, the numbers must be different.
Also see this example:
Answer String: Enter the length in cells of each of the segments labeled with numbers 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 = 4:00, Master = 6:00, Expert = 12:00