feat: day 7 bridge repair 1/2 soln, #12

Author: weaponsforge

src/2024/2024-12-06/lib/guardController.ts

@@ -19,7 +19,7 @@ export const guardController = (data: string[][], printTrail: boolean = false):
     let yDirection = 0
     let xDirection = 0
 
-    // Find the guard's direction
+    // Set the guard's direction in the grid
     switch(guard.direction) {
     case GuardDirection.UP:
       yDirection = -1

src/2024/2024-12-06/lib/guardControllerLoop.ts

@@ -32,7 +32,7 @@ export const gridHasInfiniteLoop = (
     let yDirection = 0
     let xDirection = 0
 
-    // Find the guard's direction
+    // Set the guard's direction in the grid
     switch(guard.direction) {
     case GuardDirection.UP:
       yDirection = -1

src/2024/2024-12-06/sample.test.ts

@@ -16,6 +16,6 @@ test('Count distinct guard positions', () => {
   expect(guardController(file).positionCount).toBe(26)
 })
 
-test('Count obstackle positions', () => {
+test('Count obstacle positions', () => {
   expect(findObstructionPositions(file)).toBe(2)
 })

src/2024/2024-12-07/README.md

@@ -0,0 +1,15 @@
+## Day 7: Bridge Repair
+
+Visit the Advent of Code website for more information on this puzzle at:
+
+**Source:** https://adventofcode.com/2024/day/7<br>
+**Status:** On-going ⭐
+
+## Code
+
+1. **totalCalibration.ts**
+   - `operatorCombinations()` - Finds the total number of possible combinations in which to place operator symbols for an `N`-length array
+
+   - `doEquation()` - Returns the result of an AoC text equation and a set of operator symbols with the condition: left to write equation processing, disregarding operator precedence
+
+   - `totalCalibrationResult()` - Counts the total calibration sum of input lines whose elements (numbers) match the line's target sum after processing with one of N possible combinations of `+` and `*` operands

src/2024/2024-12-07/input.txt

@@ -0,0 +1,9 @@
+190: 10 19
+3267: 81 40 27
+83: 17 5
+156: 15 6
+7290: 6 8 6 15
+161011: 16 10 13
+192: 17 8 14
+21037: 9 7 18 13
+292: 11 6 16 20

src/2024/2024-12-07/lib/totalCalibration.ts

@@ -0,0 +1,84 @@
+/**
+ * Finds the total number of possible combinations in which to place operator symbols for an `N`-length array
+ * @param {string[]} operators String array containing operator symbols
+ * @param {number} N Length of a linear array
+ * @returns {number} Total number
+ */
+const operatorCombinations = (
+  operators: string[] = ['+', '*'],
+  N: number
+) => {
+  const combinations: string[][] = []
+  const totalCombinations = Math.pow(operators.length, N)
+
+  for (let i = 0; i < totalCombinations; i += 1) {
+    const list: string[] = []
+    let seed = i
+
+    for (let j = 0; j < N; j += 1) {
+      list.push(operators[seed % operators.length] as string)
+      seed = Math.floor(seed / operators.length)
+    }
+
+    combinations.push(list)
+  }
+
+  return combinations
+}
+
+/**
+ * Returns the result of an AoC text equation and a set of operator symbols with the condition:
+ *  - Left to write equation processing, disregarding operator precedence
+ * @param {string} eqnString Math equation expressed as string
+ * @returns {number} Result of the `eqnString`
+ */
+const doEquation = (numbers: number[], operators: string[]): number => {
+  let sum = numbers[0] as number
+
+  operators.forEach((operator, index) => {
+    if (operator === '+') {
+      sum += numbers[index + 1] as number
+    }
+
+    if (operator === '*') {
+      sum *= numbers[index + 1] as number
+    }
+  })
+
+  return sum
+}
+
+/**
+ * Counts the total calibration sum of input lines whose elements (numbers) match the line's target sum
+ * after processing with one of N possible combinations of `+` and `*` operands
+ * @param input Input string array
+ * @returns {number} Total calibration sum
+ */
+export const totalCalibrationResult = (input: string[]): number => {
+  const operators = ['+', '*']
+  let sum = 0
+
+  for (let i = 0; i < input.length; i += 1) {
+    const line = input[i]
+
+    if (line === undefined) break
+    const [targetSum, data] = line.split(': ')
+    const numbers = data?.split(' ').map(Number) as number[]
+
+    // Find all operator placement combinations
+    const combinations = operatorCombinations(operators, numbers.length - 1)
+
+    // Build the text equation
+    for (let j = 0; j < combinations.length; j += 1) {
+      // Process equation
+      const result = doEquation(numbers, combinations[j] as string[])
+
+      if (result === Number(targetSum)) {
+        sum += result
+        break
+      }
+    }
+  }
+
+  return sum
+}

src/2024/2024-12-07/main.ts

@@ -0,0 +1,22 @@
+import path from 'path'
+import { AOC_OUTPUT_TYPE, readAOCInputFile } from '@/utils/aocInputFile.js'
+import { currentDirectory } from '@/utils/file.js'
+
+import { totalCalibrationResult } from './lib/totalCalibration.js'
+
+// Read and process the input file
+const input = (readAOCInputFile({
+  filePath: path.join(currentDirectory(import.meta.url), 'input.txt'),
+  type: AOC_OUTPUT_TYPE.STRING
+}) as string)
+  .split('\n')
+
+/**
+ * Part 1/2 of the 2024-12-07 quiz
+ * Counts the total calibration result of the input data
+ */
+const quiz20241221_01 = () => {
+  totalCalibrationResult(input)
+}
+
+quiz20241221_01()

src/2024/2024-12-07/sample.test.ts

@@ -0,0 +1,18 @@
+import path from 'path'
+import { test, expect } from 'vitest'
+
+import { readAOCInputFile, AOC_OUTPUT_TYPE } from '@/utils/aocInputFile.js'
+import { currentDirectory } from '@/utils/file.js'
+
+import { totalCalibrationResult } from './lib/totalCalibration.js'
+
+// Read and process the input file
+const input = (readAOCInputFile({
+  filePath: path.join(currentDirectory(import.meta.url), 'input.txt'),
+  type: AOC_OUTPUT_TYPE.STRING
+}) as string)
+  .split('\n')
+
+test('1/2: Total calibration result', () => {
+  expect(totalCalibrationResult(input)).toBe(3749)
+})

src/utils/aocInputFile.ts

@@ -25,7 +25,6 @@ type Output = string | string[] | string[][] |
  * @param param.filePath {string} Full file path to an input text file
  * @param param.type {AOC_OUTPUT_TYPE} Type to convert the input text file
  * @param param.delimiter {string} String delimiter
- * @param moduleFile {string} File URL of the current module being executed: `"import.meta.url"`
  * @throws {Error}
  */
 export const readAOCInputFile = (param: FileInput): Output => {