Sudoku is Foggy Segmented Yin Yang Snake by Andy Petersen, App variant is FOG


Normal sudoku rules apply. The grid is partially covered in fog. Correctly placed digits will remove fog from surrounding cells. Guessing is not required or recommended. Draw a one-cell wide snake of orthogonally connected cells that does not branch or touch itself. The non-snake cells must form a single, orthogonally connected area. No 2x2 region can be entirely snake or entirely non-snake. Digits separated by a white dot are consecutive. Cells separated by dots will contain one snake cell and one non-snake cell. The 3x3 box borders divide the snake into segments, each of which have the same sum.