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Abelian sandpile model/Identity: Difference between revisions
Added a Red answer
(Added Algol 68) |
(Added a Red answer) |
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Line 3,183:
│ 2 │ 3 │ 2 │ 3 │ 2 │ │ 4 │ 2 │ 2 │ 4 │ 0 │ │ 3 │ 2 │ 3 │ 2 │ 1 │ │ 5 │ 5 │ 5 │ 5 │ 3 │ │ 3 │ 2 │ 3 │ 2 │ 1 │
╰───┴───┴───┴───┴───╯ ╰───┴───┴───┴───┴───╯ ╰───┴───┴───┴───┴───╯ ╰───┴───┴───┴───┴───╯ ╰───┴───┴───┴───┴───╯
</pre>
=={{header|Red}}==
<lang Rebol>
Red [Purpose: "implement Abelian sandpile model"]
sadd: make object! [
comb: function [pile1 [series!] pile2 [series!]] [
repeat r 3 [
repeat c 3 [
pile2/:r/:c: pile2/:r/:c + pile1/:r/:c
]
]
check pile2
]
check: func [pile [series!]] [
stable: true row: col: none
repeat r 3[
repeat c 3[
if pile/:r/:c >= 4 [
stable: false
pile/:r/:c: pile/:r/:c - 4
row: r col: c
break]
]
if stable = false [break]
]
either stable = true [
print trim/with mold/only pile "[]"
] [
spill pile row col
]
]
spill: func [pile [series!] r [integer!] c [integer!]] [
neigh: reduce [
right: reduce [r c - 1] up: reduce [r + 1 c]
left: reduce [r c + 1] down: reduce [r - 1 c]
]
foreach n neigh [
unless (pile/(n/1) = none) [
unless (pile/(n/1)/(n/2) = none)
[pile/(n/1)/(n/2): pile/(n/1)/(n/2) + 1]
]
]
check pile
]
]
s1: [
[1 2 0]
[2 1 1]
[0 1 3]
]
s2: [
[2 1 3]
[1 0 1]
[0 1 0]
]
s3: [
[3 3 3]
[3 3 3]
[3 3 3]
]
s3_id: [
[2 1 2]
[1 0 1]
[2 1 2]
]
ex: [
[4 3 3]
[3 1 2]
[0 2 3]
]
sadd/check copy/deep ex
sadd/comb copy/deep s1 copy/deep s2
sadd/comb copy/deep s2 copy/deep s1
sadd/comb copy/deep s3 copy/deep s3_id
sadd/comb copy/deep s3_id copy/deep s3_id
</lang>
{{out}}
<pre>
2 1 0
0 3 3
1 2 3
3 3 3
3 1 2
0 2 3
3 3 3
3 1 2
0 2 3
3 3 3
3 3 3
3 3 3
2 1 2
1 0 1
2 1 2
</pre>
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