AoC 2024, day 22 (smalltalk)

#!/usr/local/bin/gst -q

"
| Mainline
"
part1 := 0.
count := 0.
hash  := Array new: 160000 withAll: 0.
tmp   := Dictionary new.

stdin lines contents do: [:line |
    | num last idx |

    num  := line asNumber.
    last := num \\ 10.
    idx  := 0.
    tmp empty.

    ((count := count + 1) \\ 50 == 0) ifTrue: [
        stderr nextPutAll: ('[%1] %2   ') % {count. num}; cr; flush.
    ].

    (1 to: 2000) do: [:i |
        num := ((num bitShift:  6) bitXor: num) bitAnd: 16rFFFFFF.
        num :=  (num bitShift: -5) bitXor: num.
        num := ((num bitShift: 11) bitXor: num) bitAnd: 16rFFFFFF.

        idx  := ((idx * 20) + (num \\ 10) - last + 10) \\ 160000.
        last := num \\ 10.
        (i >= 4) ifTrue: [
            tmp at: idx ifAbsentPut: [last].
        ]
    ].

    part1 := part1 + num.
    tmp keysAndValuesDo: [:idx :bananas |
        hash at: idx put: (hash at: idx ifAbsent: [0]) + bananas.
    ]
 ].

stdout nl.
('Part 1: %1' % {part1}) displayNl.
('Part 2: %1' % {hash fold: [:a :b | a max: b]}) displayNl.