2022/Day 04

Author: agrison

src/main/kotlin/me/grison/aoc/Extensions.kt

@@ -345,6 +345,14 @@ fun Iterable<Pair<Long, Long>>.pointsDisplay(empty: String = " "): String {
  return display.joinToString("\n") { it.joinToString("") }
 }
 
+fun Collection<Int>.toRange() = IntRange(this.first(), this.last())
+fun Collection<Long>.toRange() = LongRange(this.first(), this.last())
+fun Pair<Int, Int>.toRange() = IntRange(this.first, this.second)
+fun Pair<Long, Long>.toRange() = LongRange(this.first, this.second)
+
+fun IntRange.contains(range: IntRange) = this.first <= range.first && this.last >= range.last
+fun IntRange.overlap(range: IntRange) = range.first in this || range.last in this || this.first in range || this.last in range
+
 fun Collection<Int>.range() = maxOrNull()!! - minOrNull()!!
 fun Collection<Long>.range() = maxOrNull()!! - minOrNull()!!
 fun Collection<BigInteger>.range() = maxOrNull()!!.minus(minOrNull()!!)

src/main/kotlin/me/grison/aoc/Strings.kt

@@ -1,5 +1,7 @@
 package me.grison.aoc
 
+import java.util.*
+
 /** Returns the occurrences of `c`. */
 fun String.occurrences(c: Char) = count { it == c }
 
@@ -73,6 +75,7 @@ fun String.afterLast(s: String) = split(s).last()
 fun String.allInts(includeNegative: Boolean = true): List<Int> =
  (if (includeNegative) "(-?\\d+)" else "(\\d+)").regex().findAll(this).map { it.value.toInt() }.toList()
 
+fun String.allPositiveInts(): List<Int> = this.allInts(false)
 /** Returns all long found in this string. */
 fun String.allLongs(includeNegative: Boolean = true): List<Long> =
  (if (includeNegative) "(-?\\d+)" else "(\\d+)").regex().findAll(this).map { it.value.toLong() }.toList()
@@ -101,6 +104,9 @@ fun String.except(c: Char) = replace(c + "", "")
 /** Returns the string before `str`. */
 fun String.before(str: String) = split(str)[0]
 
+fun String.intRange() = this.normalSplit("-").let { IntRange(it[0].toInt(), it[1].toInt()) }
+fun String.longRange() = this.normalSplit("-").let { LongRange(it[0].toLong(), it[1].toLong()) }
+
 /** Returns the string after `str`. */
 fun String.after(str: String) = split(str)[1]
 
@@ -114,8 +120,8 @@ fun String.words() = normalSplit(" ")
 fun String.set() = stringList().toSet()
 
 fun String.`is`(s: String) = this == s
-fun String.upper() = toUpperCase()
-fun String.lower() = toLowerCase()
+fun String.upper() = uppercase(Locale.getDefault())
+fun String.lower() = lowercase(Locale.getDefault())
 
 fun String.isLower() = all { it.isLowerCase() }
 fun String.isUpper() = all { it.isUpperCase() }
@@ -142,5 +148,5 @@ fun String.split(at: Int) = listOf(this.take(at), this.drop(at))
 fun String.inTwo() = this.split(this.length / 2)
 
 fun foo() {
- "".capitalize()
+ "".replaceFirstChar { if (it.isLowerCase()) it.titlecase(Locale.getDefault()) else it.toString() }
 }

src/main/kotlin/me/grison/aoc/y2022/Day04.kt

@@ -0,0 +1,14 @@
+package me.grison.aoc.y2022
+
+import me.grison.aoc.*
+
+class Day04 : Day(4, 2022) {
+ override fun title() = "Camp Cleanup"
+
+ override fun partOne() = solve { a, b -> a.contains(b) || b.contains(a) }
+
+ override fun partTwo() = solve { a, b -> a.overlap(b) }
+
+ private fun solve(predicate: (pair1: IntRange, pair2: IntRange) -> Boolean) =
+ inputList.count { predicate(it.before(",").intRange(), it.after(",").intRange()) }
+}