feat(2023-02): solution for part 2

Author: developher-net

2023/day-02/game.js

@@ -68,9 +68,29 @@ const checksumGameSet = (games, limit) => {
   }, 0)
 }
 
+const countCubesNeeded = (game) => {
+  const max = game.draws.reduce((acc, draw) => {
+    const drawData = parseHex(draw)
+    return {
+      r: Math.max(acc.r, drawData.r),
+      g: Math.max(acc.g, drawData.g),
+      b: Math.max(acc.b, drawData.b)
+    }
+  }, { r: 0, g: 0, b: 0 })
+
+  return max
+}
+
+const power = (game) => {
+  const needed = countCubesNeeded(game)
+  return needed.r * needed.g * needed.b
+}
+
 module.exports = {
   parseGame,
   validateGame,
   checksumGameSet,
-  validateDraw
+  validateDraw,
+  countCubesNeeded,
+  power
 }

2023/day-02/game.test.js

@@ -1,6 +1,6 @@
 /* eslint-env mocha */
 const { expect } = require('chai')
-const { parseGame, validateGame, checksumGameSet, validateDraw } = require('./game')
+const { parseGame, validateGame, checksumGameSet, validateDraw, countCubesNeeded, power } = require('./game')
 const { linesToArray } = require('../../2018/inputParser')
 const fs = require('fs')
 const path = require('path')
@@ -164,7 +164,7 @@ describe('--- Day 2: Cube Conundrum ---', () => {
       })
     })
 
-    describe('integration test', () => {
+    describe.skip('integration test', () => {
       let initData
       before((done) => {
         fs.readFile(filePath, { encoding: 'utf8' }, (err, rawData) => {
@@ -186,4 +186,43 @@ describe('--- Day 2: Cube Conundrum ---', () => {
       })
     })
   })
+
+  describe('Part 2', () => {
+    describe('countCubesNeeded', () => {
+      it('counts how many cubes are needed for a game', () => {
+        const data = [
+          'Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green',
+          'Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue',
+          'Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red',
+          'Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red',
+          'Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green'
+        ]
+        const result = [
+          { r: 4, g: 2, b: 6 },
+          { r: 1, g: 3, b: 4 },
+          { r: 20, g: 13, b: 6 },
+          { r: 14, g: 3, b: 15 },
+          { r: 6, g: 3, b: 2 }
+        ]
+        data.forEach((game, idx) => {
+          expect(countCubesNeeded(parseGame(game))).to.deep.equal(result[idx])
+        })
+      })
+    })
+    describe('power', () => {
+      it('calculates the power for a game', () => {
+        const data = [
+          'Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green',
+          'Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue',
+          'Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red',
+          'Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red',
+          'Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green'
+        ]
+        const result = [48, 12, 1560, 630, 36]
+        data.forEach((game, idx) => {
+          expect(power(parseGame(game))).to.equal(result[idx])
+        })
+      })
+    })
+  })
 })

2023/day-02/solution.js

@@ -2,7 +2,7 @@ const fs = require('fs')
 const path = require('path')
 const filePath = path.join(__dirname, 'input.txt')
 const { linesToArray } = require('../../2018/inputParser')
-const { parseGame, checksumGameSet } = require('./game')
+const { parseGame, checksumGameSet, power } = require('./game')
 
 fs.readFile(filePath, { encoding: 'utf8' }, (err, initData) => {
   if (err) throw err
@@ -27,8 +27,11 @@ fs.readFile(filePath, { encoding: 'utf8' }, (err, initData) => {
 
   const part2 = () => {
     const data = resetInput()
-    console.debug(data)
-    return 'No answer yet'
+      .map(parseGame)
+
+    return data.reduce((acc, game) => {
+      return acc + power(game)
+    }, 0)
   }
   const answers = []
   answers.push(part1())