day(10): reformat and refactor
Signed-off-by: Matej Focko <mfocko@redhat.com>
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1 changed files with 21 additions and 36 deletions
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@ -3,62 +3,47 @@ package year2021.day10
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import readInput
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val CLOSING: Map<Char, Char> = mapOf(
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')' to '(',
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']' to '[',
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'}' to '{',
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'>' to '<'
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')' to '(', ']' to '[', '}' to '{', '>' to '<'
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)
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val ERROR_SCORING: Map<Char, Int> = mapOf(
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')' to 3, ']' to 57, '}' to 1197, '>' to 25137
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)
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val ERROR_SCORING: Map<Char, Int> = mapOf(')' to 3, ']' to 57, '}' to 1197, '>' to 25137)
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val AUTOCOMPLETE_SCORING: Map<Char, Long> = mapOf(
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'(' to 1,
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'[' to 2,
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'{' to 3,
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'<' to 4
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'(' to 1, '[' to 2, '{' to 3, '<' to 4
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)
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fun firstInvalid(input: String): Char? {
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fun check(input: String): Pair<Char?, List<Char>> {
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val stack = mutableListOf<Char>()
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for (c in input) {
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if (CLOSING.contains(c)) {
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// found a closing one
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if (stack.size < 1 || stack.last() != CLOSING[c]) {
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return c
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return Pair(c, stack)
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}
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stack.removeLast()
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} else {
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stack.add(c)
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}
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}
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return null
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return Pair(null, stack)
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}
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fun part1(input: List<String>): Int = input.sumOf {
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firstInvalid(it)?.let { c ->
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ERROR_SCORING[c]
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} ?: 0
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check(it).let { (c, _) ->
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ERROR_SCORING.getOrDefault(c, 0)
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}
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}
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fun getRemaining(input: String): List<Char> {
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val stack = mutableListOf<Char>()
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for (c in input) {
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if (CLOSING.contains(c)) {
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stack.removeLast()
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} else {
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stack.add(c)
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fun part2(input: List<String>): Long =
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input
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.map { check(it) }
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.filter { (c, s) -> c == null && s.isNotEmpty() }
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.map { (_, stack) ->
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stack.reversed().fold(0.toLong()) { total, c ->
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5 * total + AUTOCOMPLETE_SCORING[c]!!
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}
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}
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return stack
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}
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fun part2(input: List<String>): Long = input
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.filter { firstInvalid(it) == null }
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.map {
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getRemaining(it).reversed().fold(0.toLong()) { total, c -> 5 * total + AUTOCOMPLETE_SCORING[c]!! }
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}
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.sorted().let { scores ->
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}.sorted().let { scores ->
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scores[scores.size / 2]
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}
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