49 lines
1 KiB
Nim
49 lines
1 KiB
Nim
import ./common, std/[sequtils, algorithm, sugar, sets, strformat, strutils, tables]
|
|
|
|
proc parse(input: Lines): (string, Table[(char, char), char]) =
|
|
result[0] = input[0]
|
|
for i in 2..<input.len():
|
|
var c = input[i].split(" -> ")
|
|
result[1][(c[0][0], c[0][1])] = c[1][0]
|
|
|
|
proc stepPolymer(polymer: string, combis: Table[(char, char), char]): string =
|
|
result.add polymer[0]
|
|
var i = 1
|
|
while i < polymer.len:
|
|
var key = (polymer[i-1], polymer[i])
|
|
if combis.contains key: result.add combis[key]
|
|
result.add polymer[i]
|
|
i += 1
|
|
|
|
proc p1(input: Lines): int =
|
|
var (polymer, combis) = input.parse
|
|
for i in 1..10:
|
|
polymer = polymer.stepPolymer combis
|
|
var pps = polymer.toCountTable.values.toSeq
|
|
max(pps) - min(pps)
|
|
|
|
proc p2(input: Lines): int =
|
|
return 0
|
|
|
|
const input = """
|
|
NNCB
|
|
|
|
CH -> B
|
|
HH -> N
|
|
CB -> H
|
|
NH -> C
|
|
HB -> C
|
|
HC -> B
|
|
HN -> C
|
|
NN -> C
|
|
BH -> H
|
|
NC -> B
|
|
NB -> B
|
|
BN -> B
|
|
BB -> N
|
|
BC -> B
|
|
CC -> N
|
|
CN -> C
|
|
""".strip().split('\n').mapIt(it.strip)
|
|
doDay 14, n => n.loadInput, p1, p2, (input, 1588, 0)
|