Day 3: First try (part 1)

2 years ago · 71f8edaa7a
--- a/src/main/kotlin/day3/Day3.kt
+++ b/src/main/kotlin/day3/Day3.kt
@ -0,0 +1,63 @@
 package day3
 import java.io.File
 object Day3 {
    fun sumOfSelectedParts(file: String): Int =
        readLines(file)
            .let { lines ->
                readParts(lines)
                    .filter { parts -> parts.isSelected(lines) }
            }
            .sumOf { it.number }
    private fun readLines(file: String): List<String> =
        File(file)
            .readLines()
    fun readParts(lines: List<String>): List<Part> =
        lines
            .flatMapIndexed<String, Part> { y, line ->
                line.foldIndexed(mutableListOf()) { x, parts, character ->
                    when {
                        character.isDigit() ->
                            if (parts.lastOrNull()?.isIn(x, y) != true) {
                                val number = STARTING_NUMBERS_REGEX.find(line.substring(x))!!.value
                                parts.addLast(
                                    Part(
                                        number.toInt(),
                                        Coordinate(x, y),
                                        Coordinate(x + number.length, y)
                                    )
                                )
                            }
                    }
                    parts
                }
            }
    private val STARTING_NUMBERS_REGEX = Regex("""^\d+""")
 }
 data class Part(val number: Int, val from: Coordinate, val to: Coordinate) {
    fun isIn(x: Int, y: Int): Boolean =
        x >= from.x
                && x <= to.x
                && y >= from.y
                && y <= to.y
    fun isSelected(engine: List<String>) =
        engine.hasSymbols(from.x - 1, from.y - 1, to.x - from.x + 2) // above
                || engine.hasSymbols(from.x - 1, from.y + 1, to.x - from.x + 2) // below
                || engine.hasSymbols(from.x - 1, from.y, 1) // left
                || engine.hasSymbols(to.x + 1, from.y, 1) // right
 }
 private fun List<String>.hasSymbols(x: Int, y: Int, length: Int) =
    y > 0 && y < size - 1 && this[y].let { it.substring(maxOf(0, x), minOf(it.length, maxOf(0, x) + length)) }
        .any { !(it.isDigit() || it == '.') }
 data class Coordinate(val x: Int, val y: Int)
--- a/src/main/resources/day3/README.md
+++ b/src/main/resources/day3/README.md
@ -0,0 +1,30 @@
 --- Day 3: Gear Ratios ---
 You and the Elf eventually reach a gondola lift station; he says the gondola lift will take you up to the water source, but this is as far as he can bring you. You go inside.
 It doesn't take long to find the gondolas, but there seems to be a problem: they're not moving.
 "Aaah!"
 You turn around to see a slightly-greasy Elf with a wrench and a look of surprise. "Sorry, I wasn't expecting anyone! The gondola lift isn't working right now; it'll still be a while before I can fix it." You offer to help.
 The engineer explains that an engine part seems to be missing from the engine, but nobody can figure out which one. If you can add up all the part numbers in the engine schematic, it should be easy to work out which part is missing.
 The engine schematic (your puzzle input) consists of a visual representation of the engine. There are lots of numbers and symbols you don't really understand, but apparently any number adjacent to a symbol, even diagonally, is a "part number" and should be included in your sum. (Periods (.) do not count as a symbol.)
 Here is an example engine schematic:
    467..114..
    ...*......
    ..35..633.
    ......#...
    617*......
    .....+.58.
    ..592.....
    ......755.
    ...$.*....
    .664.598..
 In this schematic, two numbers are not part numbers because they are not adjacent to a symbol: 114 (top right) and 58 (middle right). Every other number is adjacent to a symbol and so is a part number; their sum is 4361.
 Of course, the actual engine schematic is much larger. What is the sum of all of the part numbers in the engine schematic?
--- a/src/main/resources/day3/input.txt
+++ b/src/main/resources/day3/input.txt
@ -0,0 +1,140 @@
 ..224.....487...................718.....................378............................................284........310......313..........311.
 ....*..............................*744....486*485......*......741......@...359.#666...439................*925....*......$..+........@......
 .235................758..440...........................251....*......262.....*..........*......................752......774.......515.......
 .........705%..@746........+..942*591.347.470...#..257.........637...........793.......299..../.....813....509......464......&.........688..
 .....82................................*.../..901.....*..................836.....&............814...*........*..............80...17*....*...
 .../...*...679.661.....299...........222.............875.....213...161............964...894.........998.....310....258.85...........735.586.
 .650..23..#......*.......................................760*........@./........................202...................*.....339.............
 ..............598......#.....536....702*.........705..........793......957............./........*...935...........965.......................
 ..................*.357...+.....@.......242.......*......283..*...=956.......118.......959...184...*..............*....401*527.....348...161
 .63=...955.523..77......978.846....849..........699..........790........=911.*.....87...............486.........914..............=..........
 .........*.........842......*.......*..................*127....................844...*....946.......................235...209@...710.735....
 ...........@.........*.....144....226....298........560.....253.........431......*...586.......723..../...482.......&...................*...
 ...........871../918........................+....................329*......%.....906.............*...350.....@...............365.......361..
 ......................536............................+..793..........664.....739................507......289.....256%...73..*...............
 .356..834..............*.........96.939..............28.+....=..............*...........................*................$.553..........526.
 ...*...*.............501..746....*..-.......=.................890.....+...701..............807........447......97$..%...........58......$...
 .891....346...699...........*.421......+....666......198*791......340.433............#...%...*.......................316........*.....%.....
 ..............%........81.984...........462....................../..........116...711....963...$................380.......745...85....224...
 .........370......923..@.....................563...........188+.........326*...................67.815..............*582.....................
 .........*........-........#530.........489........59...................................................#.....57.........100.*.......441*161
 .637*....961...........118...........21*...........@..216+.........................+....432*.*309..64....992.......81......=.781.644........
 .....324.........126......*166...............&...................385*..............233............*................*..436...........*517....
 .88*.........390*................355..335...372....+254..............294...$589........&..803/.....38..-...........56..$....................
 ....235.-.........+196...948....*........-................359.........................398.............608..../.................145..346.....
 ........915.................-.485.945.................936*................114.............118...............490.536..............*.%........
 .663........61.......856..........+....343....859...............*345.......*...=862............711.............................313.....606..
 ........23...$.....@..................*......................316.....529.362.............49......................307*791....................
 225...............281...#..222.....@..283..............675............*.........911*90..-.....914..%39....509...............................
 .......797*....$........23..../...895.............67.......164.896.....554.....................*............=..............460........181...
 ...........211.474...............................@...........*....*201..........911.717.#....192.75..679...........$.........*.........=....
 ....355.........................&.....................678.650......................*.....128.....*.....*.........925..230...105.............
 ....*.......409#.......*897.....698....427.........+....*.......*...............................313...670..521.......*....&.............*308
 ...838..335.................367........-..........325....233...224...950......688.....199.774.........................793.108........501....
 ...........*..102..924.349...+..595....................................*................&..............395+.....................753.........
 .........318...*......*........*....676...759.154...................524...........908.........694.211................173...........*214..424
 ....458........403...........958.98....*........*..............688......957...488..+...........*.../....................................*...
 .......*.............591...............218.....203.....196$.......+....*........*......................765......971......./....927*741..227.
 ......592..%60.$.....*.....885/....287...............................474.........409......226.174.......@........*.....230..................
 ...............162.169.................510..962..............17......................32@..*...*.................225....................-....
 .....880...................201.....823*........*...914.724.........89...&.......267=.....717.54.436..........60...............&.........69..
 710........601....306.287.....+.........65...308....&...=.../......*.....926..................................*........278.415......-.......
 ..............*..*......&..........241.%...................827../.265.............662.678......@...#......@.....$......-............734.144.
 .............424..434.....701.....*........380*731.............24.................*...&........973..741....728..357.........................
 ........304.................*...881................238.....740.........947........587...22...........................271*........603....@...
 ...................266.....918....................*..........+.519.617..*...826..........*............./268..974.........486.376....*.295...
 ...939.........363.*...............378..........302....586........*....740...=..........380........931...........................12.........
 ...*..........-.....387...............*..588..............*..../...............315...................-...712..491.........956.....#.........
 .180.454...................104..661...91...*.............811....370......471...-....419....804..........*...................*...............
 .....*.......@../464........%..*............243.....578...................&..........*...........604..250.....784....750....998.............
 .....245....165.................771...................&.......#.691...768....654....261.........................*.......*............566....
 441..................91.....194.......643...932*............379.#....$.......*.................86.............940..263.638...........*......
 ...+.............%.../.......#.........*........344...795..................991..........544....*..................*..........767...266......
 .......-..708..727.....191$......*.....698....=...................990................+.....*....308.......@......325.........*.........44...
 ...18.397....=.....93.........649.900.........62....-........322.....*.......@......339....619..........404..........540........./....*.....
 ..../...............%............................742............*...........196................874.205........96#..............203.224......
 .........704...727.................496.......*........135....769........./.................%....&....*.../..=.........757...................
 ........*........*..424..........&........714.5........*...........@....884...............114.......674.144..83..........*302...........%...
 ........29....179..*............104..................531....629.455..................473......300....................254..............640...
 ..................296.......................................................1........*.......%..............548........*.....103............
 ....381...........................365#..713.282.......%744....................../....709...#...=...431...$.*......*.....837.....*9.....*....
 ......*.90.....347.179#...................%.......359..........92............304...*.....923.446.......385.699.....749..............193.206.
 ....922.+.......*.......-197.....................*.......128........273....@.....758..............439...................650*54.736#.........
 ................817..-..........152..594..949..807.......$...224...*.....124............889.......=...................................625...
 ....139....667......239........*...........*.......387........%..806........../...........*..788....632...........=8......584-......*.%.....
 ...........*.................280...........11.........*726............181......761..-....66.....%....-................64...........14.......
 ............742.736.725..........708.667..........332.......828*750......-.........425.......................944.....*...................926
 .719...110...........*.....348...=..........121......*........................................*.......961.....*.......971...........+.......
 ..../.....*629........830..*............91....&..241..491...930............561................889....*....710.333..............163...311....
 ......%...................252.../..................*...........*270.......................165.....208.......*..................../.......694
 ...914...126...267.183........952..$645......414.822................................69.......-..........=..112.464..267....359..........*...
 .............7*..........................806.../.....931.....*.....355..............*....928...........854.........-..............*993...101
 439.897...........%...........8......381...*........*....748..987....*............437.......*....954.......................*................
 .......*595....783........49.....110.$...675...8...60.....=........981........&..........730....*.............336.......120.790..........386
 ............90..............*212...*..........*.......985.....153........*..12...912*383......665.....754.....-.....................950.....
 ......790#.*........896@.........773....777..581..514*....910.....5.....579.............................=.......#.....................*.....
 ...&.......496...........347..............*...............*...................../............................790..............334......912..
 692............609....&.......694..........693...213....620......695......871..385.......82..........785.......................*..163.......
 .........#....*......984.........*.................=............*.......................................*.545...-............978.....*......
 ......971...477.............465......196*313..........447.......766......49.......126*480.............798......792..359*193...........837...
 ................157...........+..................773.=..............752$....................447*565..........................*53............
 .384%..........@.........449............470..749...@.........@792..............138..527.......................339.....299.505...........287.
 ......691........700........@......96..........*........721*.....................@....*...942......845........*......-.........713..........
 .....*......260/...*...........................491..452.....336.......................73....+..960..........238...........163$..&...=.@.....
 ....689.............831...282....709.960.............=.............204............................#..............59...97..........199..111..
 ........................$........../........-....498......................557....&...........972............450.............................
 .............653........476...398.........619...*.....*280..923..............*31..691.........*........=...*.....67......782................
 ..............*....%..........*.........+......268...........&........428....................408....740....576....*.......*.........$.......
 ....-../...734......317.114.332...795...743.........................-..=..908...........381.......................914...420.*647....528.....
 ..284.825...............*......................721/.=929.........324.....*....167.561...*.....815*466.......................................
 ..............389..304.480.......851..@....585..............942%......#.496....*....-.53................170....938*..........518............
 ........368..*.....@..............*....941..+.......*...............930.........364.......522......................59.........+....$....652.
 ...........+.963...................949...........828.784......860............*......420.....*..................*......548...........310.*...
 .....476...............*...............=...94.+..................&........589.833....*..426.940.....&.....959.993.&88....................398
 .......*................624....917...838..*...664.......721........................833...$.......672......$............19...................
 ....350.......................&....=..............333.................707....................................240..336....=...746.263..$463..
 .........................-.........220.....663...../.............*849..#..631.....712....=.../...308.580.............*..........*...........
 .78@......../..........422....444.............*...............281............*...*....447..37.......*................814....................
 ........./...788...810.........&..............369..985....-................92................................684...............74...........
 ......279.........*......128/....464........#...../......944........978...............163..984*5.@............+.......165......*....285.....
 ..................889.............*.......969........................%.......5......&....$........272....................*......374.........
 .........&..............@948..*..13.358........796.............632............*....789........91*..............*66........152...............
 ........508...+..............3...........544.....$.517.....703....*774.......434............/....794........932.............................
 ...$...........241.....74...........974..*...954............*.......................375..772...........218.........414...........*366....252
 .501..566...............*..........*....599.....#........256.....468@..942.101.........*..........156...*.............*.......998...........
 ...../.............263.312....+..767..............#.........................*...&95..838.162=.....+....130.........583..544.......176.......
 ............................936......826.......421.......-139.......982...893.......................*..................*........./..........
 .284.....=724...................661.$....694........85..........438.............51...............616.698.*36.....262......357+........224...
 ....@..........491........+........................@......193......*596...........%../844...387.................$.....132.........%.........
 .......84..............362.................................*..98..........&................*....14....394..........$..............56........
 .........*432.....512................704......424.............*............74........196%..875...*.....*............132.......229...........
 ..............723*.........568........*..108........672......55.172...217.........................289.427........................*..........
 .........#795.........214....*.336...94....*....988................%..&.............*86......*...............838&.......540.......902.......
 .922...........288........719.....*........845...&..558......#...................524......195.704.....................................77....
 ...*....842....../...166........883...-................*503..451..305../....600............................900..280.....*169...586..........
 751....*.........../.*......944......116....416.........................877....*....418...194........644..*....=.....244..........#.....354.
 .......118......208...................................788...................826........$....$...207.....@..152...........893*608.......&....
 ..948.......................203../....206.............*....341./977.916.........49...#........@....-............+385........................
 ...*......266.................*...607...@.990......964..............-..........*.....340...697........62..............526.....-.............
 ..675.....*..........612....604.............*..............492.884...........212...............*157....*...679.........*....706...716%.518..
 ......103.749..989...*...................739..............$......=..=..................212..684.....35.......*.........785..............+...
 ..343*......../.......680.....................*423.................476....&....420..............241..*......532.....+.......864$.....&......
 ..................826........403..311...60.451.............+...........562....../.......306.......*..............420..................321...
 ...241..............*...........+..=....@......*240.......845....@.........740.................968..389.177*...................640..........
 ......*82...........963...211%...............38...............901.....404.........&..253..............-.....37.........218.501...*....320...
 ....*...........................#215...264......298........................*970..801....*....569...............3.......*......%..859.*......
 .136.818...212...........91*72........*.........-...750.....775*728.29.270...............984.&...371..........*.........639..........670....
 ...........*.../959................438.....524......*...943.........*................755...................162.................446#.........
 ..........290.............751................*.....557..*...483.............421.........*............189.%................/.................
 ....................9.786..-......835.......978........445.%..........350........860..662.......#...*....354........*.....682...............
 .117..57+....441...*....+............................................../............*.........88....142..........%.927......................
 ...*...........*..402....................874.....734.926$../...............*633......219.84/............662...205...................334.....
 ...981........367........338...332/.........=......*......119....375#.334.......146..............%.....$................384.............-511
 ........165................=....................666.....................#..614.....-..%744..617.887.......848*..............................
 ...........*.203.593...158....*..........152..............+817.....866.......&...............*......../.......904........701.165.80.........
 404..977.93..*....*....*...396.281......*....953....*................*.........116..97.70=..179....107..338................$...*....622.....
 ......=.....445........................382.....*...672................859......*...%....................&..........-.571......717....*......
 ..................240............175..........808..............225..........988............/604..............232.448..*..651......769.......
 .........569*....*........975*.....*....968..............585.....*................26.................................394....@.142...........
 ......*......498..969.........360.666...%.........................919.......360........-.*.........%...................................484..
 ...407................886...................................84......................933...101....58........839..425.........................
--- a/src/test/kotlin/day3/Day3Test.kt
+++ b/src/test/kotlin/day3/Day3Test.kt
@ -0,0 +1,12 @@
 package day3
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
 class Day3Test {
    @Test
    fun readParts() {
        assertEquals(4361, Day3.sumOfSelectedParts("src/test/resources/day3/input.txt"))
    }
 }
--- a/src/test/resources/day3/input.txt
+++ b/src/test/resources/day3/input.txt
@ -0,0 +1,10 @@
 467..114..
 ...*......
 ..35..633.
 ......#...
 617*......
 .....+.58.
 ..592.....
 ......755.
 ...$.*....
 .664.598..