feat(2019-day-02): fueling the fuel

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/part-1/fuel-calculator.test.js renamed to 2019/day-01/fuel-calculator.test.js

@@ -1,7 +1,7 @@
 const fs = require('fs')
 const path = require('path')
 const filePath = path.join(__dirname, 'input.txt')
-const { calculateFuel } = require('./fuel-calculator')
+const { calculateFuel, calculateFuelRecursively } = require('./fuel-calculator')
 const { parseData } = require('../../../2018/inputParser')
 
 fs.readFile(filePath, { encoding: 'utf8' }, (err, data) => {
@@ -15,4 +15,11 @@ fs.readFile(filePath, { encoding: 'utf8' }, (err, data) => {
 
   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}`)
 })