feat: day 4 ceres search quiz 1/2 soln, #9

Author: weaponsforge

src/2024/2024-12-01/lib/fileReader.ts

@@ -24,7 +24,6 @@ export const fileReader = (): arrayLists => {
     const pair = item.split('   ')
 
     if (pair[0] === undefined || pair[1] === undefined) {
-      console.log(pair)
       throw new Error('Undefined value')
     }
 

src/2024/2024-12-04/README.md

@@ -0,0 +1,6 @@
+## Day 4: Ceres Search
+
+Visit the Advent of Code website for more information on this puzzle at:
+
+**Source:** https://adventofcode.com/2024/day/4<br>
+**Status:** On-going

src/2024/2024-12-04/input.txt

@@ -0,0 +1,9 @@
+SAMPLEONLY
+REPLACEITW
+ACTUALAOC.
+INPUTEXT..
+ABCDEFGHIJ
+XMASXMASXM
+GMUASHLGWH
+MXAXAXMHRD
+AFHSGJM2AX

src/2024/2024-12-04/lib/wordChecker.ts

@@ -0,0 +1,105 @@
+export type CharacterArray = string[][]
+
+interface CoordinateBase {
+  x: number;
+  y: number;
+}
+
+interface Coordinate extends CoordinateBase {
+  direction: 1 | -1;
+}
+
+interface CoordinateData {
+  xDirection: 1 | -1;
+  yDirection: 1 | -1;
+  data: CharacterArray
+}
+
+/**
+ * Checks for the 'XMAS' word in the vertical directions (up/down) from an (x,y) coordinate
+ * @typedef coord {Coordinate} Coordinate object
+ * @param coord.x {number} x coordinate (array x index)
+ * @param coord.y {number} y coordinate (array y index)
+ * @param coord.direction {number} Up or down letter-checking direction
+ *   - `-1` for "up" going to (0,0)
+ *   - `1` for "down" going to (N,N) from the `coord`
+ * @param fullData {CharacterArray} 2D array of strings consisting of letters per item
+ * @param WORD {string} Word to find
+ * @returns {boolean} Flag indicating the existence of the 'XMAS' word
+ */
+export const checkVertical = (coord: Coordinate, fullData: CharacterArray, WORD: string): boolean => {
+  let yIndex = coord.y
+  let subWord = ''
+
+  if (!Array.isArray(fullData)) return false
+
+  for (let i = 0; i < WORD.length; i += 1) {
+    if (yIndex < 0) break
+    if (yIndex >= fullData.length) break
+
+    subWord += (fullData[yIndex])?.[coord.x]
+    yIndex += (coord.direction * 1)
+  }
+
+  return subWord === WORD
+}
+
+/**
+ * Checks for the 'XMAS' word in the horizontal directions (left/right) from an (x,y) coordinate
+ * @typedef coord {Coordinate} Coordinate object
+ * @param coord.x {number} x coordinate (array x index)
+ * @param coord.y {number} y coordinate (array y index)
+ * @param coord.direction {number} `-1` for "left" going to (0,0) or `1` for "right" going to (N,N) from the `coord`
+ * @param rowData {string[]} Array of row-wise letters from a 2D array
+ * @returns {boolean} Flag indicating the existence of the 'XMAS' word
+ * @param WORD {string} Word to find
+ */
+export const checkHorizontal = (coord: Coordinate, rowData: string[], WORD: string): boolean => {
+  let xIndex = coord.x
+  let subWord = ''
+
+  if (!Array.isArray(rowData)) return false
+
+  for (let i = 0; i < WORD.length; i += 1) {
+    if (xIndex < 0) break
+    if (xIndex >= rowData.length) break
+
+    subWord += rowData[xIndex]
+    xIndex += (coord.direction * 1)
+  }
+
+  return subWord === WORD
+}
+
+/**
+ * Checks for the 'XMAS' word in the horizontal directions from an (x,y) coordinate
+ * @typedef coord {Coordinate} Coordinate object
+ * @param coord.x {number} x coordinate (array x index)
+ * @param coord.y {number} y coordinate (array y index)
+ * @typedef param {CoordinateData} Direction and data object
+ * @param param.xDirection {number} `-1` for "left" going to (0,0) or `1` for "right" going to (N,N) from the `coord`
+ * @param param.yDirection {number} `-1` for "up" going to (0,0) or `1` for "down" going to (N,N) from the `coord`
+ * @param param.data {CharacterArray} 2D string array containing the input text
+ * @returns {boolean} Flag indicating the existence of the 'XMAS' word
+ * @param WORD {string} Word to find
+ */
+export const checkDiagonal = (coord: CoordinateBase, param: CoordinateData, WORD: string): boolean => {
+  let xIndex = coord.x
+  let yIndex = coord.y
+  let subWord = ''
+
+  if (!Array.isArray(param.data)) return false
+  if (param.data[0] === undefined) return false
+
+  for (let i = 0; i < WORD.length; i += 1) {
+    if (xIndex < 0 || xIndex >= param.data[0].length) break
+    if (yIndex < 0 || yIndex >= param.data.length)  break
+
+    subWord += (param.data[yIndex])?.[xIndex]
+
+    xIndex += (param.xDirection * 1)
+    yIndex += (param.yDirection * 1)
+  }
+
+  return subWord === WORD
+}

src/2024/2024-12-04/lib/wordCount.ts

@@ -0,0 +1,82 @@
+import { checkVertical, checkHorizontal, checkDiagonal } from './wordChecker.js'
+
+/**
+ * Counts the number of occurence of the 'XMAS' word from a set of input
+ * @param data {CharacterArray} 2D string array containing the input text
+ * @param WORD_TO_FIND {string} Word to find
+ * @returns {number} Number of 'XMAS' words
+ */
+export const wordCount = (data: string[][], WORD_TO_FIND: string): number => {
+  let xmasCount = 0
+  const firstLetter = WORD_TO_FIND[0]
+
+  for (let y = 0; y < data.length; y += 1) {
+    const row = data[y]
+
+    if (!Array.isArray(row)) continue
+
+    if (row.filter(
+      item => typeof item !== 'string').length > 0
+    ) continue
+
+    for (let x = 0; x < row.length; x += 1) {
+      const letter = row[x]
+
+      if (letter !== firstLetter) continue
+
+      // Check WORD_TO_FIND down
+      if (checkVertical(
+        { x, y, direction: 1 }, data, WORD_TO_FIND)) xmasCount += 1
+
+      // Check WORD_TO_FIND up
+      if (checkVertical(
+        { x, y, direction: -1 }, data, WORD_TO_FIND)) xmasCount += 1
+
+      // Check WORD_TO_FIND right
+      if (checkHorizontal(
+        { x, y, direction: 1 }, row, WORD_TO_FIND)) xmasCount += 1
+
+      // Check WORD_TO_FIND left
+      if (checkHorizontal(
+        { x, y, direction: -1 }, row, WORD_TO_FIND)) xmasCount += 1
+
+      // Check WORD_TO_FIND diagonally right-up
+      if (checkDiagonal(
+        { x, y },
+        { xDirection: 1, yDirection: -1, data },
+        WORD_TO_FIND
+      )) {
+        xmasCount += 1
+      }
+
+      // Check WORD_TO_FIND diagonally right-down
+      if (checkDiagonal(
+        { x, y },
+        { xDirection: 1, yDirection: 1, data },
+        WORD_TO_FIND
+      )) {
+        xmasCount += 1
+      }
+
+      // Check WORD_TO_FIND diagonally left-up
+      if (checkDiagonal(
+        { x, y },
+        { xDirection: -1, yDirection: -1, data },
+        WORD_TO_FIND
+      )) {
+        xmasCount += 1
+      }
+
+      // Check WORD_TO_FIND diagonally left-down
+      if (checkDiagonal(
+        { x, y },
+        { xDirection: -1, yDirection: 1, data },
+        WORD_TO_FIND
+      )) {
+        xmasCount += 1
+      }
+    }
+  }
+
+  return xmasCount
+}

src/2024/2024-12-04/main.ts

@@ -0,0 +1,16 @@
+import path from 'path'
+import { currentDirectory, readFile } from '@/utils/file.js'
+import { wordCount } from './lib/wordCount.js'
+
+const directory = currentDirectory(import.meta.url)
+
+const data: string[][] = readFile(path.join(directory, 'input.txt'))
+  .split('\n')
+  .map(row => row.split(''))
+
+const quiz20241204_01 = () => {
+  const count = wordCount(data, 'XMAS')
+  console.log('"XMAS" word count:', count)
+}
+
+quiz20241204_01()

src/2024/2024-12-04/sample.test.ts

@@ -0,0 +1,14 @@
+import { test, expect } from 'vitest'
+import { wordCount } from './lib/wordCount.js'
+
+const data: string[][] = `ABCDEFGHIJ
+XMASXMASXM
+GMUASHLGWH
+MXAXAXMHRD
+AFHSGJM2AX`
+  .split('\n')
+  .map(row => row.split(''))
+
+test('Count "XMAS" words - demo', () => {
+  expect(wordCount(data, 'XMAS')).toBe(3)
+})