From ef57c0df338dc3897d0cfec969daf66f787d4540 Mon Sep 17 00:00:00 2001
From: Bart Riemens <briemens@crafity.com>
Date: Thu, 7 Dec 2023 21:43:51 +0100
Subject: [PATCH] 2023 - Day 3

---
 2023/03/PART1.md    |  46 +++++++++++++++
 2023/03/PART2.md    |  44 ++++++++++++++
 2023/03/input.txt   | 140 ++++++++++++++++++++++++++++++++++++++++++++
 2023/03/sample.txt  |  10 ++++
 2023/03/solution.ts |  98 +++++++++++++++++++++++++++++++
 5 files changed, 338 insertions(+)
 create mode 100644 2023/03/PART1.md
 create mode 100644 2023/03/PART2.md
 create mode 100644 2023/03/input.txt
 create mode 100644 2023/03/sample.txt
 create mode 100644 2023/03/solution.ts

diff --git a/2023/03/PART1.md b/2023/03/PART1.md
new file mode 100644
index 0000000..ba89a9c
--- /dev/null
+++ b/2023/03/PART1.md
@@ -0,0 +1,46 @@
+--- 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.
+...$.*....
+.664.598..
+```
+
+In this schematic, two numbers are not part numbers because they are not
+adjacent to a symbol: 114 (top right) and 58 (middle right). Every other number
+is adjacent to a symbol and so is a part number; their sum is 4361.
+
+Of course, the actual engine schematic is much larger. What is the sum of all of
+the part numbers in the engine schematic?
diff --git a/2023/03/PART2.md b/2023/03/PART2.md
new file mode 100644
index 0000000..cc3f31d
--- /dev/null
+++ b/2023/03/PART2.md
@@ -0,0 +1,44 @@
+--- Part Two ---
+
+The engineer finds the missing part and installs it in the engine! As the engine
+springs to life, you jump in the closest gondola, finally ready to ascend to the
+water source.
+
+You don't seem to be going very fast, though. Maybe something is still wrong?
+Fortunately, the gondola has a phone labeled "help", so you pick it up and the
+engineer answers.
+
+Before you can explain the situation, she suggests that you look out the window.
+There stands the engineer, holding a phone in one hand and waving with the
+other. You're going so slowly that you haven't even left the station. You exit
+the gondola.
+
+The missing part wasn't the only issue - one of the gears in the engine is
+wrong. A gear is any * symbol that is adjacent to exactly two part numbers. Its
+gear ratio is the result of multiplying those two numbers together.
+
+This time, you need to find the gear ratio of every gear and add them all up so
+that the engineer can figure out which gear needs to be replaced.
+
+Consider the same engine schematic again:
+
+```
+467..114..
+...*......
+..35..633.
+......#...
+617*......
+.....+.58.
+..592.....
+......755.
+...$.*....
+.664.598..
+```
+
+In this schematic, there are two gears. The first is in the top left; it has
+part numbers 467 and 35, so its gear ratio is 16345. The second gear is in the
+lower right; its gear ratio is 451490. (The * adjacent to 617 is not a gear
+because it is only adjacent to one part number.) Adding up all of the gear
+ratios produces 467835.
+
+What is the sum of all of the gear ratios in your engine schematic?
diff --git a/2023/03/input.txt b/2023/03/input.txt
new file mode 100644
index 0000000..14a7579
--- /dev/null
+++ b/2023/03/input.txt
@@ -0,0 +1,140 @@
+...................305.124................................432..............................................576..313.....514.................
+.............113...-......&....................&...819...........654..../..........................&901................*....869.257.........
+...377..&783../.................................9...........855*......940..463................-.........................844.*....@......679.
+......*...........197.261.....817..336.759............&742......548.......&........748......844.............#.......&........254...169..*...
+.......36....368.*...............*....*.........*..88......%866.......135.........*..................515.682.....114...%...........*.....768
+...233......*....909..698.........427..........127.*...................*...........450.........482..../.................312.....621.........
+.../.......882...............776...................555......180.........971....217.......857.../........212....674.917......736.....441*760.
+............................*.....@....907....%940.....%.......+.#..........45*...........$............#..........*...............=.........
+..................370.225.425..211...................932..........381..267.............45.....=....549....238........367..&.....488.........
+.468.............*.......................761...677.......&.................929..907.....%....79...*.......*....324..*....515................
+....-.#103.504...388...........$..........*.....@........766.%................*....*623.........532..881...573....*..840..............497...
+...........*.........305....412..687.......971................676....@640....657........709......................807............98.....+....
+....279...502...62...*.............*..............................................838%.....$.........585..........................*.........
+....=...=......*....209.825.482.993..........972............620*664..-759............................*.......184.........952....160.....156.
+.......814.....931......*...*............551..*....711...65.................224*115...851.772..104..505.....=........796*...................
+....................723.103..275........*......564..*.........830........................*...../..............................232...........
+.............$......&....................951........703......=............160+.....138......*........257*809.............$298........284....
+.....684....464.333..................827.....*211..................................#.....855.86.....................$913............*.......
+.......*...........*..*......917.163....*.409......294.......................#..39.......................511....358.......$671.......237....
+.......663.......311..163....*...%...158........*....-.442.........958....108.....#.....941*837.........*..........*........................
+............865=..........409....................128...*.......283....................................680.........730.935@........768.......
+....../................=.............54.....857.........418.....*..911.......610..643............381...............................@........
+.......925............984...........-...800*.................194.../.........*.......*.........../.....................................@....
+.................................@...............................&......615...16....695.....-..........................*750.............855.
+....611..136...................108.540.........362..711......*....420.....................190.......................213.............86......
+204*....@.........288..825..+........&...........*....*......733.........................................7..387.......................*.....
+...........795..../.......+.505.834.....228....192...619..........886......467.....942.............................%838.........512...340...
+.......957.........................*...*..................962........................*..............211...$..............624................
+.......*....................349....144......./786..350.......*.......................541..21.......$.....284..190*......*............518....
+....484...@....17..........*..../........309..........*....530...118..........208..............253................489.828...........*.......
+..........309...........715.....531........+.516#...645.........$........369....*.......*185...@............=.#...........@............&....
+491*192..............................................................233.........711.948.........572.....869..289......932...........149....
+........274.....511.....425..........421.288*965...652=.919........./....*.786...........676.....*..................+.........=.............
+.........*.........@......$...*.........................*........*....791...+..113......*....527..897..499+.904...166........580.........389
+.......306.....................353.497..929/.......=....553......495.................884.....&........................794........774........
+...................../...........................582....................................................489..........*...............&......
+.605......537.....247.....................479................74................227*995.761.....@...........+.......958...87.....547.795.....
+...*.....*....................289+.....*.....%........967..............*...............*........611.....28....367.................*.........
+..690....916.497....................894.440......547$.............596.492......23...............................*...............237.221..786
+.........................681.....=..........580+.................+...............+.......696............@..542..56..........................
+...936..639*947.............+...48.*709..................307.257...-248.697.553.............+.........146.....#.......*241..................
+...*................568....................=378....41.......*............*...%..11......*..........................982.............#........
+..323..704.+724..*....*..195*....812..879...........*.....*....508@.....852....$.....664.......317....*......332..............326.158.......
+.......*........610..767.....936...#...&..744.290..839.382.543....................................&.827...../.............323*.........884..
+...........962...............................*...................46....502.265.150...................................639...............*....
+955*818.......*...@...124*512..256...................+....&..............*....*.......170....996...#........................786.......4.....
+..............284.697...........*......172...........398.435.......-.....380..........+..........698....428...361................206........
+.822...#..............936$...745..........*..%59..................726...........+.........249......../...*.....*..................%.........
+.....870................................978.......761=.......179.............692.........*..........477..550.....676..281.............507...
+..............913.................215.........................*..745...#.............882..130..569....................&..........*472..*....
+...27..710.....*.....................*.205*403..............59....+..172................=.............................................697...
+....*....*....731.......865.......155..........849*....#..............................................679...854....................&........
+.985..%.............599....#..........191..520.......473..#........./...........708....406..677+...=............................599.....133.
+......501...........*........@.........*...*..............446....767...*444........@......&.........49......#...311*413.....................
+..................157.......830..13.90.398.945.978............................950.................%.......88................$...............
+.............297........618.......+.*............%............317.............../.........709..481............503.........570...305*845.....
+......661....*....632.....@..+......524......../.....+...........*...590..............944....*...............*................+..........681
+.......*.....820...@..........829...........671.......206.......239.+......................339..#............106......415..213..........-...
+........114........................903.669=............................764...319....373........642...................................-......
+.................*...........................*.......121.......898&.....$......*...*.....................................211#.......579.....
+........*.......362......787.440..........842.825.....*......................590...357..........949......523....470..292....................
+.....594.459........98.....*....*.......................355&..*..................*..........554..*.......*.......*....*..222...243..........
+.........................535.....674.........804....#..........455.............847............=.32...23..951.....217.346....+.*....+272.....
+..183...........443..........119.......833....#..693......818#........................@..699..............................*....678..........
+...*......455/...%..826.............#.....*.........................$...........868.739....=..753...181....773.........323.508..............
+...382................*...169..510..590.295....212.767....*970......711.........*........#.......*..*............651...........36..766*.....
+............&..61..697.....*................46.*....*..691......970............786....953.....775...235..................*550....*.....417..
+..........45.....*........689...645.....549*...821.601.............*......................952..............#..........464.....609...........
+.....657.........48...888.......*...................................305......+47..........................254.27......................123...
+818......388............*....412....../491.........#336...506..422.................989....15...70..............*..354............@.....*....
+..............506........11......./...........643..........#..=..........703...963*........@.........613.....413....%...485.......265...33..
+....589.......*................207..............%...............................................+................*......*.....94............
+...*.........663...413+....................................819...........655.%...648..823.......770....385......457..150...#.../............
+515.......................475....825......33../350.....459...%..........*....681...*...*..............%..................437.......689......
+....$993..897@..............*.......*837...-...........*..............726........372....922......&198................................*......
+180............*..........679.................71.629=.796......109...........................527..................682.....558.....798.......
+........437.742.46.................@.......&...................*......498.......@.............*............./......$........*...............
+..761..$...........148.......856....701.377..536*510...604...540.....&........929........172.799.............310.....700...........440.%....
+.....*........808*....=.........@......................*.........577.....................*................&...........$...417.39.....&.229..
+........794.......446..............................214.543...%...*..........935......865..445...../....%.615................=..*............
+..572..+...............................419....932@.........924..72.902.......-..579.-...........997.203................873......945..567....
+.....*.................273.............*...........................*...142............688................755.850...........846.........=....
+...880................*..............883.698.....$.......=........197.*...........316*.........365.........$...*............*............904
+.........385..977..179....+...................652......875.............350...863............73......464.........214.852..478................
+......22....*..@.........93............*682..................*137..309.........*....557.....*........................=.......698.....+.218..
+......*...645......163...............89......*853..................*...386..341.......*...228............718*492...............*..153..*....
+.....576......................857.........513....................509......*.....322.710.........615.......................613.165.......292.
+................................@.....370.......598......487...........503..*.....................*...738#..#..$901...$.....#.......648.....
+..19*454.............78................/..876..#..........*......+..........937.......383........523........69......326.678.....212....*....
+.....................*.....436.@...646...*..........100....367..325.....361.......207*....50............621...............*..........237....
+757.........714......502...%...54......909.411.....*.....................*..........................=..$................415.................
+...$.......&.................................*...471..985...508.472....891.842..$.................418.........&.....&.......................
+.................$........906..........*215.338...............*..............*..606.#235......................813..259........229...........
+........472...222.........*.....245.572.......................927...769....344.............291.239.....................94....*..............
+...818...$.............291..............288...........163.734......+...........699............*.......981&...514*.............224.....=.....
+.....*..................................*.........................................+..189..........452............644...................669..
+....850................326$..............869..&985......784..../..............592.......*..153.....*....887..493.....211........%...........
+.............................457....834.....................94..564..........&.........498....*...304....../...*.....*..........845.....&...
+.......12*48.753...244..196....=......$..721....90*29.........*.................+.522.......487...............317.....531..311........20....
+.177...............*.....*.................*.............*969.611.......*565..338...*.............712..922$.......770......*....522.........
+....*..459......149......165...=........879...........103............497..........258.931..75....*..........400*.....*......972.............
+.269...*............#........715.............................*475..........................*....145.............414.....228........893......
+........209......508...................../331......469....894............347.890$..541.....56...............#........#..*...................
+......................=...........37................*...........................................$...........197...119.....=...........756...
+...........&.......850.....367.34...*............517........178*716..........=...................892......-............883...755............
+.....@496.125.................*......965.....428.....908..................405.....650...................=..493..89..........................
+..............581........396.............596.........*....964........672......159.%....463............768......./.............391...........
+.............*...........*.....871.660..*......577.73......@.....932....#....*............*574...186........154......996........*......720..
+............914..132..137......=.......746......*..................*......376.......&661............*560.%.......%....*...264....511........
+...%...151................*851...................................*..284.........754..........190.19.......611...326.841...............89....
+644.....*...797........133.....476..............................810.............*.....866......+.*..............................#903..*.....
+........839..*..478...........*........372.#.....744.....227*............477.3.253.%....&..746.....289.&860.....720*708.....................
+............443...%.....68*....283.......%..900...%....%..........584......*.$......308....*......*......................592................
+...239................@....250........50........&...%...192.$111.*........74............831....914...#.....886*492..........=...............
+...*......425.....181..680..............*......873.502............93.................................503.@..............116........372......
+492..........*.....$.............302...789.................861.......................290.......452........83....626....*.....76.......*.....
+......178...528..........*739...@..........................*......804....320....#.........&878.*.....746........./..&...148...$......741....
+...&....*.............262..............325...........599..592.579.....%...+..808...............386..*...............761.....................
+663..462...........*..........109..706*.................=.............553........712......*971......674.396...635*..........................
+........../...728.952...413......*......744.......%..........................300..*....782................*.......742..&424........41+...564
+........375...%.........*......450.456.$.........714........851.327..#...+......*...+.......179.630....854..................................
+..251................195...887.....*........*209.......430.*......-.83.596....956..966.274.%.....*........................83.359........411.
+....%.......................*..........89.........194..+...491.........................&.....*.762..+741..........598.......*.....910..*....
+..........618+..............677........*..598........+..........-.....58....290...........795...........................*.....580.&....559..
+...................561..............910......-..321....834....602.752*....=..+........191..............463....@..........792..*.............
+............216.......%...722*668.....................$..................109............*....222...195*.......689....380.......637..........
+.....846.......*..436..............=827...263@.764*.......*.464.................729.....934...*......................................289+...
+.127*.......757.....&......./954...................965..664........./......716*.+...........266....781.........989..........844...$.........
+................57.....................&118......=...........385.623...245..............345........*.....615-.....*..........*...768........
+...538...........#..860......................783.460..........*............401.............*796..354..............37......797........725.193
+....*..#620../.........*..........578..54...*..........780..251...634..946....*........................./....702........................*...
+..202.......815........724....#..............822..972...................$..........*.....#....@........27.....*...........268.....347.......
+.................+..........98.....703..............&....*52.....320.............670...318....734.............47..................+....239..
+.953*919...=......273................=...454.....@....601...........*...958.........................+.................758...=...............
+..........905./50.........@...................971..................762.*..................169........915.682..........=......533.......502..
+.....884.................24...........262.........@.....531..698.......234.................................................%.......149..*...
+....................834.....994.......*........266.....*......*............................................/.....941.434...812.......*..211.
+.............133......*......*.....613...85..........871.......497..346...737....88.....176.....192$........128.*.......&......./163.26.....
+....734..543....*.....656....461........*......531..................*........../...*..&................$971.....931.........................
+................606....................506............................779.......30...211.....243..........................153...504.........
diff --git a/2023/03/sample.txt b/2023/03/sample.txt
new file mode 100644
index 0000000..b20187f
--- /dev/null
+++ b/2023/03/sample.txt
@@ -0,0 +1,10 @@
+467..114..
+...*......
+..35..633.
+......#...
+617*......
+.....+.58.
+..592.....
+......755.
+...$.*....
+.664.598..
diff --git a/2023/03/solution.ts b/2023/03/solution.ts
new file mode 100644
index 0000000..809bbda
--- /dev/null
+++ b/2023/03/solution.ts
@@ -0,0 +1,98 @@
+const sample = await Deno.readTextFile("sample.txt");
+const input = await Deno.readTextFile("input.txt");
+
+interface Result<T> {
+  value: T;
+  line: number;
+  length: number;
+  index: number;
+}
+
+const isSymbol = (char: string): boolean =>
+  char !== undefined && isNaN(parseFloat(char)) && char !== ".";
+
+const isGear = (char: string): boolean => char === "*";
+
+const hasSurrounding = (
+  dataMap: string[],
+  { line, index, length }: Result<number>,
+  predicate: (char: string) => boolean,
+): { row: number; column: number }[] => {
+  const result: { row: number; column: number }[] = [];
+  for (let row = line - 1; row <= line + 1; row += 1) {
+    for (let column = index - 1; column < index + length + 1; column += 1) {
+      if (predicate(dataMap[row]?.[column])) result.push({ row, column });
+    }
+  }
+  return result;
+};
+
+const solvePart1 = (data: string): number => {
+  const dataMap = data
+    .split("\n")
+    .filter(Boolean);
+
+  return dataMap.map((line, index) =>
+    Array.from(
+      line.matchAll(/\d+/g),
+      (x): Result<number> => ({
+        value: parseFloat(x[0]),
+        line: index,
+        length: x[0].length,
+        index: x.index ?? -1,
+      }),
+    )
+  ).flat()
+    .reduce(
+      (sum, result) =>
+        hasSurrounding(dataMap, result, isSymbol).length
+          ? sum + result.value
+          : sum,
+      0,
+    );
+};
+
+console.log("Sample:", solvePart1(sample)); // 4361
+console.log("Input", solvePart1(input)); // 550934
+
+const solvePart2 = (data: string): number => {
+  const dataMap = data
+    .split("\n")
+    .filter(Boolean);
+
+  const numbersPerGear = dataMap.map((line, index) =>
+    Array.from(
+      line.matchAll(/\d+/g),
+      (x): Result<number> => ({
+        value: parseFloat(x[0]),
+        line: index,
+        length: x[0].length,
+        index: x.index ?? -1,
+      }),
+    )
+  ).flat()
+    .map(
+      (result) => ({
+        ...result,
+        gears: hasSurrounding(dataMap, result, isGear),
+      }),
+    ).reduce((group, result): Record<string, number[]> => {
+      result.gears.forEach((gear) => {
+        group[`${gear.row}:${gear.column}`] = [
+          ...(group[`${gear.row}:${gear.column}`] || []),
+          result.value,
+        ];
+      });
+      return group;
+    }, {} as Record<string, number[]>);
+
+  return Object.values(numbersPerGear).reduce(
+    (sum, result) =>
+      result.length > 1 ? sum + result.reduce((s, v) => s * v) : sum,
+    0,
+  );
+
+};
+
+console.log("Sample2:", solvePart2(sample)); // 467835
+console.log("Input", solvePart2(input)); // 81997870