87 lines
2.2 KiB
Nim
87 lines
2.2 KiB
Nim
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import std/[strutils, tables]
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import lib/[loader, util]
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type
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Bag = object
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adj: string
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color: string
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BagCount = object
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bag: Bag
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count: int
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Rule = object
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outer: Bag
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contents: seq[BagCount]
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proc `==`(a, b: Bag): bool =
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a.adj == b.adj and a.color == b.color
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func parseBag(spec: string): Bag =
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[adj, color] <- spec.split()
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result = Bag(adj: adj, color: color)
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func parseRule(spec: string): Rule =
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[outer, inner] <- spec.split(" bags contain ")
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let outerBag = parseBag(outer)
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var bagCounts: seq[BagCount]
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if inner != "no other bags.":
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# make sure to strip "bags." off the end of the contents
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for bc_spec in inner[0..^6].split(", "):
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[count, bag_spec] <- bc_spec.split(maxsplit = 1)
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let bc = BagCount(
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bag: parseBag(bag_spec),
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count: parseInt(count)
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)
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bagCounts.add(bc)
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result = Rule(
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outer: parseBag(outer),
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contents: bagCounts
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)
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proc loadRules(): Table[Bag, Rule] =
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for line in loadStrings(7):
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let rule = parseRule(line)
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result[rule.outer] = rule
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proc partOne(rules: Table[Bag, Rule]): int =
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# inner function so we can capture the "rules" var I guess?
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proc find(rule: Rule, target: Bag): bool =
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for bagCount in rule.contents:
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if bagCount.bag == target:
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return true
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elif find(rules[bagCount.bag], target):
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return true
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return false
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let b = Bag(adj: "shiny", color: "gold")
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for _, r in rules:
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if find(r, b):
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result += 1
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proc partTwo(rules: Table[Bag, Rule]): int =
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# ok so that worked, let's do it again
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proc sumContents(bag: Bag): int =
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for bagCount in rules[bag].contents:
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result += bagCount.count # for the inner bag itself
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result += bagCount.count * sumContents(bagCount.bag)
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# "x contains no other bag" is a no-op, so returns default 0
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let b = Bag(adj: "shiny", color: "gold")
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result = sumContents(b)
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when isMainModule:
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let rules = loadRules()
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echo "One: ", partOne(rules)
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echo "Two: ", partTwo(rules)
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