Normal sudoku rules apply.
There are penguins running around in this sudoku. A clue outside the grid that begins with a P is a penguin clue. If a square has a penguin clue next to it, it means a penguin begins its journey in that square. The clue tells you how many squares the penguins will visit, including the starting square.
A penguin will always move into another square if it is able to. It can only enter a square that is orthogonally connected to the square it is in. (So it never moves diagonally.) A penguin will never enter a square it has already been to.
(To be clear: A penguin always ends its journey because it has visited all the squares that are orthogonally connected to the square it is in. If that is not the case, it cannot end it’s journey just because it has used up all the steps in its penguin clue.)
When choosing between possible squares it can move to, the penguin will choose the square with the smallest number (Because penguins like it cold.) If there are two possible squares with the same smallest number, the penguin prefers moving horizontally (left or right) instead of vertically (up or down.)
A clue outside the grid that begins with an S is a sandwich clue. A sandwich clue shows the sum of the digits between the 1 and the 2 in that row or column.
Example:
The green squares are the numbers adding up to 9 in the sandwich clue. The red line shows the path of the penguin.
The puzzle:
solving online: penpa
Solution code: Row 1. No gaps between numbers.
on 5. March 2021, 11:44 by davidagg
A rabbit warren of logic!
on 3. March 2021, 14:44 by Thorsby
Clarefied rules
on 3. March 2021, 13:22 by Phistomefel
Hello Thorsby! A brief question: Does the penguin's journey always have to end in a cul-de-sac like in the example or can it also end in a cell with a neighbor it could still visit if it wasn't for the cell limit of the journey?
[Thorsby] Always in a cul-de-sac.
on 2. March 2021, 21:24 by MagnusJosefsson
Wonderful! Truly a unique and interesting puzzle, quite a stiff challenge as well!
[Thorsby]Thank you!