Merge pull request #42 from amclin/feature/2019-day-02

Feature/2019 day 02

2019/day-02/input.txt

@@ -0,0 +1 @@
+1,0,0,3,1,1,2,3,1,3,4,3,1,5,0,3,2,1,10,19,2,6,19,23,1,23,5,27,1,27,13,31,2,6,31,35,1,5,35,39,1,39,10,43,2,6,43,47,1,47,5,51,1,51,9,55,2,55,6,59,1,59,10,63,2,63,9,67,1,67,5,71,1,71,5,75,2,75,6,79,1,5,79,83,1,10,83,87,2,13,87,91,1,10,91,95,2,13,95,99,1,99,9,103,1,5,103,107,1,107,10,111,1,111,5,115,1,115,6,119,1,119,10,123,1,123,10,127,2,127,13,131,1,13,131,135,1,135,10,139,2,139,6,143,1,143,9,147,2,147,6,151,1,5,151,155,1,9,155,159,2,159,6,163,1,163,2,167,1,10,167,0,99,2,14,0,0

2019/day-02/intcodeParser.js

@@ -0,0 +1,59 @@
+const add = ({ posIn1, posIn2, posOut, data }) => {
+  console.debug(`Adding ${data[Number(posIn1)]} to ${data[Number(posIn2)]}`)
+  data[posOut] = data[Number(posIn1)] + data[Number(posIn2)]
+  return true
+}
+
+const multiply = ({ posIn1, posIn2, posOut, data }) => {
+  console.debug(`Multiplying ${data[Number(posIn1)]} with ${data[Number(posIn2)]}`)
+  data[posOut] = data[Number(posIn1)] * data[Number(posIn2)]
+  return true
+}
+
+const terminate = ({ instructionPointer }) => {
+  console.log(`Reached terminator at instructionPointer ${instructionPointer}. Stopping.`)
+  return false
+}
+
+const step = ({ instructionPointer, data }) => {
+  console.debug(`Step: ${instructionPointer}`)
+  const opCodesMap = {
+    1: add,
+    2: multiply,
+    99: terminate
+  }
+  const instruction = data.slice(instructionPointer, instructionPointer + 4)
+  const opcode = instruction[0]
+
+  // Run the correct opcode for the specified step
+  return opCodesMap[opcode]({
+    posIn1: instruction[1],
+    posIn2: instruction[2],
+    posOut: instruction[3],
+    data,
+    instructionPointer
+  })
+}
+
+const runProgram = ({ data }) => {
+  let instructionPointer = 0
+  let running = true
+
+  // Convert to BigInts because operations will exceed 53bit integers
+  // TODO: Standard chokes on this ES2020 feature. Remove eslint-disable
+  // once fixed.
+  // See https://github.com/standard/standard/issues/1436
+  // eslint-disable-next-line no-undef
+  data.forEach((key, idx) => { data[idx] = BigInt(key) })
+
+  while (running === true && instructionPointer <= data.length) {
+    const instructionLength = 4
+    running = step({ instructionPointer, data })
+    instructionPointer += instructionLength
+  }
+}
+
+module.exports = {
+  step,
+  runProgram
+}

2019/day-02/intcodeParser.test.js

@@ -0,0 +1,61 @@
+/* eslint-env mocha */
+const expect = require('chai').expect
+const { step, runProgram } = require('./intcodeParser')
+
+describe('--- 2019 Day 2: 1202 Program Alarm ---', () => {
+  describe('Part 1', () => {
+    describe('intcodeParser', () => {
+      describe('step()', () => {
+        it('can add', () => {
+          const oppcode = 1
+          const data = [oppcode, 5, 6, 3, 99, 2, 3]
+          step({ instructionPointer: 0, data })
+          expect(data[3]).equals(5)
+        })
+        it('can multiply', () => {
+          const oppcode = 2
+          const data = [oppcode, 5, 6, 3, 99, 2, 3]
+          step({ instructionPointer: 0, data })
+          expect(data[3]).equals(6)
+        })
+        it('can terminate', () => {
+          const oppcode = 99
+          const data = [oppcode, 5, 6, 3, 99, 2, 3]
+          step({ instructionPointer: 0, data })
+          expect(data[3]).equals(3)
+        })
+      })
+    })
+    describe('runProgram()', () => {
+      it('runs through sequential steps of an intCode program', () => {
+        const testInputs = [
+          [1, 0, 0, 0, 99],
+          [2, 3, 0, 3, 99],
+          [2, 4, 4, 5, 99, 0],
+          [1, 1, 1, 4, 99, 5, 6, 0, 99]
+        ]
+        const testOutputs = [
+          [2, 0, 0, 0, 99],
+          [2, 3, 0, 6, 99],
+          [2, 4, 4, 5, 99, 9801],
+          [30, 1, 1, 4, 2, 5, 6, 0, 99]
+        ]
+        // Convert outputs to BigInts
+        testOutputs.forEach((out, idx) => {
+          out.forEach((value, idx2) => {
+            // TODO: Standard chokes on this ES2020 feature. Remove eslint-disable
+            // once fixed.
+            // See https://github.com/standard/standard/issues/1436
+            // eslint-disable-next-line no-undef
+            testOutputs[idx][idx2] = BigInt(value)
+          })
+        })
+
+        testInputs.forEach((data, idx) => {
+          runProgram({ data })
+          expect(data).to.deep.equal(testOutputs[idx])
+        })
+      })
+    })
+  })
+})

2019/day-02/solution.js

@@ -0,0 +1,67 @@
+const fs = require('fs')
+const path = require('path')
+const filePath = path.join(__dirname, 'input.txt')
+const { runProgram } = require('./intcodeParser')
+const { inputToArray } = require('../../2018/inputParser')
+
+fs.readFile(filePath, { encoding: 'utf8' }, (err, initData) => {
+  if (err) throw err
+
+  initData = inputToArray(initData.trim())
+
+  const resetInput = () => {
+    // Deep copy to ensure we aren't mutating the original data
+    return JSON.parse(JSON.stringify(initData))
+  }
+
+  const part1 = () => {
+    const data = resetInput()
+    // Manipulate input per puzzle instructions for Part 1
+    data[1] = 12
+    data[2] = 2
+    runProgram({ data })
+    return data[0]
+  }
+
+  const part2 = ({ target, maxNoun, maxVerb }) => {
+    // Helper for running the program with specified noun and verb inputs
+    const tryProgram = ({
+      noun,
+      verb
+    }) => {
+      const data = resetInput()
+      data[1] = noun
+      data[2] = verb
+      runProgram({ data })
+      console.debug(`Running with noun:${noun} and verb:${verb} produces ${data[0]}`)
+      return Number(data[0])
+    }
+
+    // Manipulate and loop through attempts for Part 2
+    let noun = -1
+    while (noun <= maxNoun) {
+      let verb = -1
+      noun++
+      while (verb <= maxVerb) {
+        verb++
+        const output = tryProgram({
+          noun,
+          verb
+        })
+        // Break the search loop on success
+        if (output === target) {
+          return 100 * noun + verb
+        }
+      }
+    }
+  }
+
+  const answer1 = part1()
+  const answer2 = part2({ target: 19690720, maxNoun: 99, maxVerb: 99 })
+
+  console.log('-- Part 1 --')
+  console.log(`Answer: ${answer1}`)
+
+  console.log('-- Part 2 --')
+  console.log(`Answer: ${answer2}`)
+})

README.md

@@ -3,7 +3,12 @@
 [![codecov](https://codecov.io/gh/amclin/advent-of-code/branch/master/graph/badge.svg)](https://codecov.io/gh/amclin/advent-of-code)
 
 ### Special Instructions
+Run by modifying `index.js` to point to the puzzle you want to execute.
 
-#### Day 14
+#### 2019:Day 02
+Day 2 requires the use of BigInt which is added to Javascript in ES2020 and I didn't include a polyfill.
+This limits the solution to [Javascript engines with BigInt support](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt#Browser_compatibility)
+
+#### 2018:Day 14
 Day 14 is fast but needs more memory to complete. Run node with 4GB of heap space:
 `node --max_old_space_size=4096 index.js`

index.js

@@ -1 +1 @@
-require('./2019/day-01/part-1/solution')
+require('./2019/day-02/solution')