Random Shortest Path (PuzzleScript Script) https://www.puzzlescript.net/play.html?p=fb4dc9e8c2ee33a8aeabbf2d43646b4d

script.txt

title Random Shortest Path
author Dennis Au
background_color Green
run_rules_on_level_start
========
OBJECTS
========
Background .
White

Wall X
Grey

Player @
Black
.....
.000.
.000.
.000.
.....

Fill0 0
Black
.....
.....
.....
.....
.....

Fill1 1
Black
.....
.....
.....
.....
.....

Fill2 2
Black
.....
.....
.....
.....
.....

ToR
Blue
.....
....0
....0
....0
.....

FromL
Blue
.....
.....
0....
.....
.....

ToD
Blue
.....
.....
.....
.....
.000.

FromU
Blue
..0..
.....
.....
.....
.....

ToL
Blue
.....
0....
0....
0....
.....

FromR
Blue
.....
.....
....0
.....
.....

ToU
Blue
.000.
.....
.....
.....
.....

FromD
Blue
.....
.....
.....
.....
..0..

=======
LEGEND
=======
Fill = Fill0 or Fill1 or Fill2
To = ToR or ToD or ToL or ToU
From = FromR or FromD or FromL or FromU
Arrow = To or From

=======
SOUNDS
=======

================
COLLISIONLAYERS
================
Background
Fill
Player, Wall
ToR, FromR
ToD, FromD
ToL, FromL
ToU, FromU

======
RULES
======

(use floodfill to mark distance to player alternating 0,1,2...
algorithm is:

1. Mark Player as 0
2. Mark unfilled squares next to 0 as 1
3. Mark unfilled squares next to 1 as 2
4. Mark unfilled squares next to 2 as 0
5. Loop 2-4.

Then, enemies can find the player by reducing their distance by one:
1. If enemy is on 2, mark to move to 1
2. If enemy is on 1, mark to move to 0
3. If enemy is on 0, mark to move to 2
)

late [Player] -> [Player Fill0]

late  [Fill0 | No Fill No Wall] -> [Fill0 | Fill1]
+late [Fill1 | No Fill No Wall] -> [Fill1 | Fill2]
+late [Fill2 | No Fill No Wall] -> [Fill2 | Fill0]

late [Arrow] -> []

late right [Fill1 | Fill0] -> [ToR Fill1 | FromL Fill0]
late down  [Fill1 | Fill0] -> [ToD Fill1 | FromU Fill0]
late left  [Fill1 | Fill0] -> [ToL Fill1 | FromR Fill0]
late up    [Fill1 | Fill0] -> [ToU Fill1 | FromD Fill0]

late right [Fill2 | Fill1] -> [ToR Fill2 | FromL Fill1]
late down  [Fill2 | Fill1] -> [ToD Fill2 | FromU Fill1]
late left  [Fill2 | Fill1] -> [ToL Fill2 | FromR Fill1]
late up    [Fill2 | Fill1] -> [ToU Fill2 | FromD Fill1]

late right [Fill0 | Fill2] -> [ToR Fill0 | FromL Fill2]
late down  [Fill0 | Fill2] -> [ToD Fill0 | FromU Fill2]
late left  [Fill0 | Fill2] -> [ToL Fill0 | FromR Fill2]
late up    [Fill0 | Fill2] -> [ToU Fill0 | FromD Fill2]

late [Fill] -> []

==============
WINCONDITIONS
==============

=======
LEVELS
=======

.xxx.....@
.x...x....
.x.xxxxxx.
.x.x...@x.
xx.x....x.
...x....x.
.xxx....x.
........x.
x.xxxxxxx.
x.........
x..xx.....
x.........
xxxxxxxxxx