67 lines
1.7 KiB
Kotlin
67 lines
1.7 KiB
Kotlin
package aoc2024
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import println
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import readInput
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import splitInts
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/*
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--- Day 2: Red-Nosed Reports ---
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https://adventofcode.com/2024/day/2
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*/
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fun main() {
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val inlineTestInput = """
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7 6 4 2 1
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1 2 7 8 9
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9 7 6 2 1
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1 3 2 4 5
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8 6 4 4 1
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1 3 6 7 9
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"""
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fun checkGood(i: List<Int>): Boolean {
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val dir = i[1] - i[0]
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return if (dir < 0) {
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!i.runningReduce { acc, elem -> if ((elem < acc) and (elem >= acc - 3)) elem else Int.MIN_VALUE }
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.contains(Int.MIN_VALUE)
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} else if (dir > 0) {
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!i.runningReduce { acc, elem -> if ((elem > acc) && (elem <= acc + 3)) elem else Int.MAX_VALUE }
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.contains(Int.MAX_VALUE)
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} else {
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false
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}
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}
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fun part1(input: List<String>): Int {
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return input.map { it.splitInts() }.count(::checkGood)
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}
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fun part2(input: List<String>): Int {
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val ilist = input.map { it.splitInts() }
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var sum = 0
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for (i in ilist) {
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for (dp in ilist.indices) {
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if (checkGood(i.filterIndexed { index, _ -> dp != index })) {
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sum++
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break
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}
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}
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}
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return sum
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}
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// test if implementation meets criteria from the description, like:
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val testInput = inlineTestInput.trim().reader().readLines()
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//val testInput = readInput("aoc2024/Day02_test")
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val testInputPart1Result = part1(testInput)
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println("Part 1 Test: $testInputPart1Result")
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val testInputPart2Result = part2(testInput)
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println("Part 2 Test: $testInputPart2Result")
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check(testInputPart1Result == 2)
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check(testInputPart2Result == 4)
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val input = readInput("aoc2024/Day02")
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part1(input).println()
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part2(input).println()
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}
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