Merge pull request #41 from amclin/feature/2019-day-01

Feature/2019 day 01

Author: developher-net

2019/day-01/fuel-calculator.js

@@ -0,0 +1,25 @@
+const calculateFuel = (mass) => {
+  return Math.max(
+    0,
+    Math.floor(mass / 3) - 2
+  )
+}
+
+const sumMassWithFuel = (mass) => {
+  const fuel = calculateFuel(mass)
+  if (fuel <= 0) {
+    return mass
+  }
+
+  return mass + sumMassWithFuel(fuel)
+}
+
+const calculateFuelRecursively = (mass) => {
+  // For fuel calcs, exclude initial mass
+  return sumMassWithFuel(mass) - mass
+}
+
+module.exports = {
+  calculateFuel,
+  calculateFuelRecursively
+}

2019/day-01/fuel-calculator.test.js

@@ -0,0 +1,36 @@
+/* eslint-env mocha */
+const expect = require('chai').expect
+const { calculateFuel, calculateFuelRecursively } = require('./fuel-calculator')
+
+describe('--- 2019 Day 1: The Tyranny of the Rocket Equation ---', () => {
+  describe('Part 1', () => {
+    describe('calculateFuel()', () => {
+      it('calculates the fuel amount for a specified mass', () => {
+        const inputs = [12, 14, 1969, 100756]
+        const outputs = [2, 2, 654, 33583]
+
+        inputs.forEach((input, idx) => {
+          expect(calculateFuel(input)).equals(outputs[idx])
+        })
+      })
+      it('will not output negative quantities for fuel', () => {
+        const inputs = [0, 1, -2345]
+        const outputs = [0, 0, 0]
+
+        inputs.forEach((input, idx) => {
+          expect(calculateFuel(input)).equals(outputs[idx])
+        })
+      })
+    })
+    describe('calculateFuelRecursively()', () => {
+      it('calculates fuel amount for a specified mass, along with the fuel for the fuel', () => {
+        const inputs = [14, 1969, 100756]
+        const outputs = [2, 966, 50346]
+
+        inputs.forEach((input, idx) => {
+          expect(calculateFuelRecursively(input)).equals(outputs[idx])
+        })
+      })
+    })
+  })
+})

2019/day-01/input.txt

@@ -0,0 +1,100 @@
+114739
+132732
+123925
+146385
+72590
+51932
+64164
+72919
+97336
+101791
+101477
+95677
+89907
+76998
+60782
+109021
+138070
+113374
+68672
+133830
+134079
+89079
+72321
+142643
+102734
+103743
+77864
+111363
+72140
+64483
+139567
+141318
+132736
+87824
+81937
+123404
+56730
+54447
+63602
+84561
+145159
+93598
+137770
+52943
+146307
+91674
+143183
+52543
+143052
+107171
+80699
+130825
+141406
+75771
+123497
+87982
+144545
+125153
+147925
+106898
+60193
+111251
+102454
+135886
+141408
+84556
+94143
+97958
+86474
+96848
+126314
+51037
+140379
+142065
+73629
+102432
+123801
+68146
+107720
+51512
+123873
+104308
+59601
+149175
+80400
+76822
+116115
+87990
+90592
+68688
+133868
+78357
+91425
+149328
+123010
+93278
+101150
+120352
+107642
+136050

2019/day-01/solution.js

@@ -0,0 +1,25 @@
+const fs = require('fs')
+const path = require('path')
+const filePath = path.join(__dirname, 'input.txt')
+const { calculateFuel, calculateFuelRecursively } = require('./fuel-calculator')
+const { parseData } = require('../../../2018/inputParser')
+
+fs.readFile(filePath, { encoding: 'utf8' }, (err, data) => {
+  if (err) throw err
+
+  data = parseData(data.trim())
+
+  const answer = data.reduce((prev, cur) => {
+    return prev + calculateFuel(parseInt(cur))
+  }, 0)
+
+  console.log('-- Part 1 --')
+  console.log(`Answer: ${answer}`)
+
+  const answer2 = data.reduce((prev, cur) => {
+    return prev + calculateFuelRecursively(parseInt(cur))
+  }, 0)
+
+  console.log('-- Part 2 --')
+  console.log(`Answer: ${answer2}`)
+})

index.js

@@ -1 +1 @@
-require('./2018/day-14/solution')
+require('./2019/day-01/part-1/solution')