cbcvm: 6.585 total, Python: 10.573 total

day23part2.py

from itertools import count
from lib.input import fetch


def main():
    class node:
        __slots__ = "label", "next"

        def __init__(self, label):
            self.label = label
            self.next = None

    data = fetch().strip()
    all_cups = list(map(int, data))
    for i in range(max(all_cups) + 1, 1_000_000 + 1):
        all_cups.append(i)

    lookup = [None] * 1_000_001
    current = cups = lookup[all_cups[0]] = node(all_cups[0])
    for label in all_cups[1:]:
        cups.next = lookup[label] = node(label)
        cups = cups.next
    cups.next = current

    min_cup = min(all_cups)
    max_cup = max(all_cups)

    for move in count(1):
        a = current.next
        b = a.next
        c = b.next
        current.next = c.next

        dest = current.label - 1
        if dest < min_cup:
            dest = max_cup
        while dest == a.label or dest == b.label or dest == c.label:
            dest -= 1
            if dest < min_cup:
                dest = max_cup

        dest_node = lookup[dest]
        end = dest_node.next
        dest_node.next = a
        c.next = end

        current = current.next

        if move == 10_000_000:
            break

    one = lookup[1]
    print(one.next.label * one.next.next.label)


if __name__ == "__main__":
    main()

day23part2.rbcvm

import array;
import arraylist;
import char;
import fs;
import hash;
import hashmap;
import iter;
import string;

function main() {
    let data = string.strip(
        fs.read_file("../advent-of-code-2020/days/day23/input.txt"),
    );

    struct node { label, next }

    let all_cups = arraylist.from_array(
        string.length(data),
        array.map(string.chars(data), char.to_digit),
    );

    let max_cup = iter.max(arraylist.to_iter(all_cups));

    for (let i = max_cup + 1; i < 1000001; i = i + 1) {
        arraylist.push(all_cups, i);
    }

    all_cups = arraylist.to_array(all_cups);

    let lookup = array.new(1000001);
    let first_node = node { label = all_cups[0] };
    lookup[all_cups[0]] = first_node;
    let cups = first_node;
    let current = cups;

    let len = array.length(all_cups);
    for (let i = 1; i < len; i = i + 1) {
        let label = all_cups[i];
        lookup[label] = cups = cups:next = node { label = label };
    }
    cups:next = current;

    let min_cup = iter.min(all_cups),
        max_cup = iter.max(all_cups);

    for (let move = 0;; move = move + 1) {
        let a = current:next;
        let b = a:next;
        let c = b:next;
        current:next = c:next;

        let dest = current:label - 1;
        if (dest < min_cup) {
            dest = max_cup;
        }
        while (dest == a:label || dest == b:label || dest == c:label) {
            dest = dest - 1;
            if (dest < min_cup) {
                dest = max_cup;
            }
        }

        let dest_node = lookup[dest];
        let end = dest_node:next;
        dest_node:next = a;
        c:next = end;

        current = current:next;

        if (move == 10000000) {
            break;
        }
    }

    let one = lookup[1];
    println(one:next:label * one:next:next:label);
}

main();