feat: day 5 print queue quiz 1/2 soln, #10

Author: weaponsforge

src/2024/2024-12-05/README.md

@@ -0,0 +1,13 @@
+## Day 5: Print Queue
+
+Visit the Advent of Code website for more information on this puzzle at:
+
+**Source:** https://adventofcode.com/2024/day/5<br>
+**Status:** On-going
+
+<br>
+
+| Code | Description |
+| --- | --- |
+| **orderedUpdates.ts** | Has functions for finding correct "updates" according to defined "rules." It also counts the sum of middle page numbers from correctly-ordered "updates." |
+| **fileReader.ts** | Reads and transforms a text file for processing by the quiz scripts. |

src/2024/2024-12-05/input.txt

@@ -0,0 +1,28 @@
+39|89
+101|15
+101|95
+101|39
+5|48
+95|15
+5|89
+48|15
+101|48
+89|48
+95|89
+101|89
+95|48
+39|15
+5|39
+101|5
+39|95
+5|95
+39|48
+5|15
+89|15
+
+5,39,95,89,48
+101,95,89,48,15
+5,48,15
+5,101,39,95,89
+95,15,48
+101,15,5,48,39

src/2024/2024-12-05/lib/fileReader.ts

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+import path from 'path'
+import { currentDirectory, readFile } from '@/utils/file.js'
+import { uniformArrayElements } from '@/utils/arrays.js'
+
+export type Rules = Record<number, number[]>
+
+export type QuizData = {
+  rules: Rules;
+  updates: number[][]
+}
+
+/**
+ * Reads and transforms quiz input text for processing.
+ * @param fileName {string} Filename of input text relative to the calling function
+ * @returns {QuizData} Formatted data
+ */
+export const fileReader = (fileName: string): QuizData => {
+  const directory = currentDirectory(import.meta.url)
+  const file = readFile(path.join(directory, '..', fileName))
+
+  const segments = file.split('\n\n')
+
+  if (
+    segments[0] === undefined ||  // rules
+    segments[1] === undefined     // updates
+  ) {
+    throw new Error('Undefined rules or updates data')
+  }
+
+  const rules: Rules = segments[0]
+    .split('\n')
+    .reduce((list: Rules, item) => {
+      const pair: number[] = item.split('|').map(Number)
+
+      if (!uniformArrayElements(pair, 'number')) {
+        throw new Error('Invalid rules value')
+      }
+
+      const key = pair[0] as number
+
+      if (list[key] === undefined) {
+        list[key] = [pair[1] as number]
+      } else {
+        list[key].push(pair[1] as number)
+      }
+
+      return list
+    }, {})
+
+  return {
+    rules,
+    updates: segments[1]
+      .split('\n')
+      .map(item => item.split(',').map(Number))
+  }
+}

src/2024/2024-12-05/lib/orderedUpdates.ts

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+import type { QuizData, Rules } from './fileReader.js'
+import { uniformArrayElements, arrayMiddleIndex } from '@/utils/arrays.js'
+
+/**
+ * Checks if an "update" list is correct according to defined "rules"
+ * @param rules {Rules} Object containing parsed and formatted rules and updates data
+ * @param updateItems {number[]} "updates" item content
+ * @returns Flag indicating if the set of `updateItems` is correct
+ */
+export const isOrderedReport = (rules: Rules, updateItems: number[]): boolean => {
+  let isOrdered = true
+
+  if (!uniformArrayElements(updateItems, 'number')) {
+    throw new Error('Invalid updateItems item/s')
+  }
+
+  for (let i = 0; i < updateItems.length - 1; i += 1) {
+    const currentItem = updateItems[i] as number
+
+    // Current "update" item should have en entry in the "rules" object
+    if (rules[currentItem] === undefined) {
+      isOrdered = false
+      break
+    }
+
+    // Get the rest of items after the current item for comparison
+    const afterItems = updateItems.filter((_, index) => index > i)
+
+    // Current item's "rule" should have the after-item entries
+    if (!afterItems.every(item => rules[currentItem]?.includes(item))) {
+      isOrdered = false
+      break
+    }
+
+    // Backtrack current item's inclusion in previous item maps
+    if (i > 0) {
+      for (let j = 0; j < i; j += 1) {
+        const beforeItem = updateItems[j] as number
+
+        if (rules[beforeItem] === undefined) {
+          isOrdered = false
+          break
+        }
+
+        if (!rules[beforeItem].includes(currentItem)) {
+          isOrdered = false
+          break
+        }
+      }
+    }
+  }
+
+  return isOrdered
+}
+
+/**
+ * Counts the sum of middle page numbers from correctly-ordered "updates"
+ * @param data {QuizData} Object containing "rules" and "updates" input
+ * @param verbose {boolean} Flag to display processing log messages. Defaults to false.
+ * @returns {number}
+ */
+export const sumOfCorrectUpdates = (data: QuizData, verbose: boolean = false): number => {
+  let sum = 0
+
+  for (let i = 0; i < data.updates.length; i += 1) {
+    const isOrdered = isOrderedReport(data.rules, data.updates[i] ?? [])
+
+    if (isOrdered) {
+      if (verbose) {
+        console.log('---correct', data.updates[i])
+      }
+
+      const mid = arrayMiddleIndex(data.updates[i] as number[])
+      const item = data.updates[i]?.[mid - 1]
+      sum += item ?? 0
+    }
+  }
+
+  return sum
+}

src/2024/2024-12-05/main.ts

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+import { fileReader } from './lib/fileReader.js'
+import { sumOfCorrectUpdates } from './lib/orderedUpdates.js'
+import type { QuizData } from './lib/fileReader.js'
+
+const data: QuizData = fileReader('input.txt')
+
+/**
+ * Part 1/2 of the 2024-12-05 quiz
+ * Counts the sum of middle pages from correct updates
+ */
+const quiz20241205 = () => {
+  const sum = sumOfCorrectUpdates(data, true)
+  console.log('Sum of middle page numbers:', sum)
+}
+
+quiz20241205()

src/2024/2024-12-05/sample.test.ts

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+import { test, expect } from 'vitest'
+import { sumOfCorrectUpdates } from './lib/orderedUpdates.js'
+import { fileReader } from './lib/fileReader.js'
+import type { QuizData } from './lib/fileReader.js'
+
+const data: QuizData = fileReader('input.txt')
+
+test('Count middle pages - demo', () => {
+  expect(sumOfCorrectUpdates(data)).toBe(232)
+})

src/utils/arrays.ts

@@ -18,3 +18,24 @@ export const arrangeArray = (order: ARRAY_ORDERING) =>
       throw new Error('Invalid ordering')
     }
   }
+
+/**
+ * Checks if array elements have the same type and has no null or undefined values
+ * @param items {S[]} array of elements
+ * @param type {T} type name of the elements inside the `items` array
+ * @returns {boolean} Flag indicating if all array elements have the same type
+ */
+export const uniformArrayElements = <S, T>(items: S[], type: T): boolean => {
+  return (
+    items.filter(value => typeof value === type).length === items.length
+  )
+}
+
+/**
+ * Retrieves the middle (center) index of an array
+ * @param list {T[]} 1-dimensional array
+ * @returns {number} Middle index of an array
+ */
+export const arrayMiddleIndex = <T>(list: T[]): number => {
+  return Math.floor(list.length / 2) + list.length % 2
+}