Heavy Fog At The Airport
- Fog of war
- Thermometers
- Whisper lines
- Minimum and maximum cells
- Fortress
The brief
Standard sudoku rules apply: each row column and 3x3 box must contain all the digits from 1 to 9.
Fog: most of the airport is covered by fog. Placing a digit correctly in a cell will remove the fog from that cell and the adjacent cells.
German Whispers: adjacent digits on a green line must have a difference of at least 5.
Maximum: a digit in a grey square must be greater than all digits in cells orthognally adjacent to it.
Thermometers: digits along grey lines must strictly increase from the bulb to the tip.