Logic Masters Deutschland e.V.

It's Snake feeding time! In this sudoku variant four hungry snakes fight for food trying to grow.
I had a lot of fun setting this sudoku because I didn't expect the idea to work that well.
The basic idea is to look at the numbers in sudoku as snake food. The rules determine which next food cell a snake will pick. The corresponding cell then becomes part of the snake and the starting point for the next step. In this way paths of orthogonally connected cells are created, as known from other snake puzzles. The decisive factor, however, is the interaction of the snakes. The "fight" for food cells and how it is decided which snake prevails. All the rules are listed below. Have fun!

Sudoku at Penpa+

Rules:

1. Normal sudoku rules apply.

2. The coloured cells are the four snakes. The cell with the rounded shape is the head.

3. The snakes "eat" one of the cells orthogonally adjacent to the head. This cell becomes part of the snake and is its new head.

4. Size and agility: The size of a snake is given by the sum of the digits in its cells (not the number of cells!). The smaller the snake, the more agile it is.

5. A snake always picks the largest possible food cell that it can get according to the following restrictions.
- A snake can only eat food if at that point it is already at least 3 times the size of the food.
- Gray cells are stones and cannot be eaten.
- If two snakes were to eat the same food, the more agile snake wins (i.e. the smaller one up to this point (sum!)). The other snake picks the next best option. If both snakes are equally agile, they will occupy the cell at the same time, thereby killing each other. Don't let that happen!
- When a snake has the choice between two identical, largest possible food cells, it always chooses the one for which it has to turn 90°.
- A hungry snake doesn't care about touching itself orthogonally. It is only interested in the largest possible food.

6. All four snakes must get to their respective hiding places at the correct size. The hiding places are the colored cells outside the grid. The number in this cells indicate how big the snake has to be when it reaches the cell. A snake goes in its hiding place as soon as it reaches the cell next to it, even if more food is available.