feat: solve advent of code 2016 day 1 part 1

Author: JCPedroza

src/advent-of-code/2016/01-no-time-for-a-taxicab/input-big.txt

@@ -0,0 +1 @@
+R3, L5, R1, R2, L5, R2, R3, L2, L5, R5, L4, L3, R5, L1, R3, R4, R1, L3, R3, L2, L5, L2, R4, R5, R5, L4, L3, L3, R4, R4, R5, L5, L3, R2, R2, L3, L4, L5, R1, R3, L3, R2, L3, R5, L194, L2, L5, R2, R1, R1, L1, L5, L4, R4, R2, R2, L4, L1, R2, R53, R3, L5, R72, R2, L5, R3, L4, R187, L4, L5, L2, R1, R3, R5, L4, L4, R2, R5, L5, L4, L3, R5, L2, R1, R1, R4, L1, R2, L3, R5, L4, R2, L3, R1, L4, R4, L1, L2, R3, L1, L1, R4, R3, L4, R2, R5, L2, L3, L3, L1, R3, R5, R2, R3, R1, R2, L1, L4, L5, L2, R4, R5, L2, R4, R4, L3, R2, R1, L4, R3, L3, L4, L3, L1, R3, L2, R2, L4, L4, L5, R3, R5, R3, L2, R5, L2, L1, L5, L1, R2, R4, L5, R2, L4, L5, L4, L5, L2, L5, L4, R5, R3, R2, R2, L3, R3, L2, L5

src/advent-of-code/2016/01-no-time-for-a-taxicab/input-huge.txt

@@ -0,0 +1 @@
+R3, L5, R1, R2, L5, R2, R3, L2, L5, R5, L4, L3, R5, L1, R3, R4, R1, L3, R3, L2, L5, L2, R4, R5, R5, L4, L3, L3, R4, R4, R5, L5, L3, R2, R2, L3, L4, L5, R1, R3, L3, R2, L3, R5, L194, L2, L5, R2, R1, R1, L1, L5, L4, R4, R2, R2, L4, L1, R2, R53, R3, L5, R72, R2, L5, R3, L4, R187, L4, L5, L2, R1, R3, R5, L4, L4, R2, R5, L5, L4, L3, R5, L2, R1, R1, R4, L1, R2, L3, R5, L4, R2, L3, R1, L4, R4, L1, L2, R3, L1, L1, R4, R3, L4, R2, R5, L2, L3, L3, L1, R3, R5, R2, R3, R1, R2, L1, L4, L5, L2, R4, R5, L2, R4, R4, L3, R2, R1, L4, R3, L3, L4, L3, L1, R3, L2, R2, L4, L4, L5, R3, R5, R3, L2, R5, L2, L1, L5, L1, R2, R4, L5, R2, L4, L5, L4, L5, L2, L5, L4, R5, R3, R2, R2, L3, R3, L2, L5, R3, L5, R1, R2, L5, R2, R3, L2, L5, R5, L4, L3, R5, L1, R3, R4, R1, L3, R3, L2, L5, L2, R4, R5, R5, L4, L3, L3, R4, R4, R5, L5, L3, R2, R2, L3, L4, L5, R1, R3, L3, R2, L3, R5, L194, L2, L5, R2, R1, R1, L1, L5, L4, R4, R2, R2, L4, L1, R2, R53, R3, L5, R72, R2, L5, R3, L4, R187, L4, L5, L2, R1, R3, R5, L4, L4, R2, R5, L5, L4, L3, R5, L2, R1, R1, R4, L1, R2, L3, R5, L4, R2, L3, R1, L4, R4, L1, L2, R3, L1, L1, R4, R3, L4, R2, R5, L2, L3, L3, L1, R3, R5, R2, R3, R1, R2, L1, L4, L5, L2, R4, R5, L2, R4, R4, L3, R2, R1, L4, R3, L3, L4, L3, L1, R3, L2, R2, L4, L4, L5, R3, R5, R3, L2, R5, L2, L1, L5, L1, R2, R4, L5, R2, L4, L5, L4, L5, L2, L5, L4, R5, R3, R2, R2, L3, R3, L2, L5

src/advent-of-code/2016/01-no-time-for-a-taxicab/part-a/ntfta-delta-one-if.js

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+/**
+ * Computes the block distance of a destination based on input instructions.
+ * Uses differences (deltas) to represent directions, and one 'if' chain to
+ * change direction.
+ *
+ * Time complexity: O(n)
+ * Space complexity: O(n)
+ *
+ * @param {string} instr Movement instructions.
+ * @returns {number} Block distance from the destination.
+ */
+const blockDistance = (instr) => {
+  const splitIns = instr ? instr.split(', ') : []
+  let x = 0
+  let y = 0
+  let dx = 0
+  let dy = 1
+
+  for (const ins of splitIns) {
+    const turn = ins[0]
+    const dist = parseInt(ins.slice(1))
+
+    // Update direction deltas based on turn.
+    if (turn === 'L') { // 90° counterclockwise
+      const temp = dx
+      dx = -dy
+      dy = temp
+    } else { // 90° clockwise
+      const temp = dx
+      dx = dy
+      dy = -temp
+    }
+
+    // Update distance based on direction deltas.
+    x += dist * dx
+    y += dist * dy
+  }
+
+  return Math.abs(x) + Math.abs(y)
+}
+
+module.exports = {
+  fun: blockDistance,
+  id: 'distance-delta one-if'
+}

src/advent-of-code/2016/01-no-time-for-a-taxicab/part-a/ntfta-num-two-if.js

@@ -0,0 +1,39 @@
+/**
+ * Computes the block distance of a destination based on input instructions.
+ * Uses numbers to represent directions, modulo operator to change direction,
+ * and two small 'if' chans to change direction and distance separately.
+ *
+ * Time complexity: O(n)
+ * Space complexity: O(n)
+ *
+ * @param {string} instr Movement instructions.
+ * @returns {number} Block distance from the destination.
+ */
+const blockDistance = (instr) => {
+  const splitIns = instr ? instr.split(', ') : []
+  let x = 0
+  let y = 0
+  let dir = 0 // 0: north, 1: east, 2: south, 3: west
+
+  for (const ins of splitIns) {
+    const turn = ins[0]
+    const dist = parseInt(ins.slice(1))
+
+    // Update direction based on turn.
+    if (turn === 'L') dir = (dir + 3) % 4
+    else dir = (dir + 1) % 4
+
+    // Update distance based on direction.
+    if (dir === 0) y += dist
+    else if (dir === 1) x += dist
+    else if (dir === 2) y -= dist
+    else x -= dist
+  }
+
+  return Math.abs(x) + Math.abs(y)
+}
+
+module.exports = {
+  fun: blockDistance,
+  id: 'distance-num two-if'
+}

src/advent-of-code/2016/01-no-time-for-a-taxicab/part-a/ntfta-str-one-big-if.js

@@ -0,0 +1,63 @@
+/**
+ * Computes the block distance of a destination based on input instructions.
+ * Uses strings to represent directions, and one big 'if' chain to change
+ * distance and direction.
+ *
+ * Time complexity: O(n)
+ * Space complexity: O(n)
+ *
+ * @param {string} instr Movement instructions.
+ * @returns {number} Block distance from the destination.
+ */
+const blockDistance = (instr) => {
+  const splitIns = instr ? instr.split(', ') : []
+  let x = 0
+  let y = 0
+  let dir = 'N'
+
+  for (const ins of splitIns) {
+    const turn = ins[0]
+    const dist = parseInt(ins.slice(1))
+
+    if (dir === 'N') {
+      if (turn === 'L') {
+        x -= dist
+        dir = 'W'
+      } else {
+        x += dist
+        dir = 'E'
+      }
+    } else if (dir === 'S') {
+      if (turn === 'L') {
+        x += dist
+        dir = 'E'
+      } else {
+        x -= dist
+        dir = 'W'
+      }
+    } else if (dir === 'W') {
+      if (turn === 'L') {
+        y -= dist
+        dir = 'S'
+      } else {
+        y += dist
+        dir = 'N'
+      }
+    } else {
+      if (turn === 'L') {
+        y += dist
+        dir = 'N'
+      } else {
+        y -= dist
+        dir = 'S'
+      }
+    }
+  }
+
+  return Math.abs(x) + Math.abs(y)
+}
+
+module.exports = {
+  fun: blockDistance,
+  id: 'distance-str one-big-if'
+}

src/advent-of-code/2016/01-no-time-for-a-taxicab/part-a/ntfta.repo.js

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+const ntftaStrOneBigIf = require('./ntfta-str-one-big-if')
+const ntftaNumTwoIf = require('./ntfta-num-two-if')
+const ntftaDeltaOneIf = require('./ntfta-delta-one-if')
+
+const solutions = [
+  ntftaStrOneBigIf,
+  ntftaNumTwoIf,
+  ntftaDeltaOneIf
+]
+
+module.exports = solutions

src/advent-of-code/2016/01-no-time-for-a-taxicab/part-a/ntfta.test.js

@@ -0,0 +1,26 @@
+const { describe, it } = require('node:test')
+const assert = require('assert/strict')
+
+const { readFileSync } = require('fs')
+const { join } = require('path')
+
+const solutions = require('./ntfta.repo')
+
+const bigInputPath = join(__dirname, '../input-big.txt')
+const bigInput = readFileSync(bigInputPath, 'utf-8')
+
+for (const { fun, id } of solutions) {
+  describe(`Advent of Code 'No Time for a Taxicab' solution '${id}'`, () => {
+    it('solves for empty directions', () => {
+      assert.equal(fun(''), 0)
+    })
+
+    it('solves for two directions', () => {
+      assert.equal(fun('R2, L3'), 5)
+    })
+
+    it('solves big-sized directions (solves the puzzle)', () => {
+      assert.equal(fun(bigInput), 236)
+    })
+  })
+}

src/advent-of-code/2016/01-no-time-for-a-taxicab/part-a/ntfta.time.js

@@ -0,0 +1,14 @@
+const { readFileSync } = require('fs')
+const { join } = require('path')
+
+const { timeAndReport } = require('../../../../../lib/time')
+const solutions = require('./ntfta.repo')
+
+const hugeInputPath = join(__dirname, '../input-huge.txt')
+const hugeInput = readFileSync(hugeInputPath, 'utf-8')
+
+const args = [hugeInput]
+const runs = 25_000
+const id = 'Advent of Code 2016 day 1 part 1 (huge input)'
+
+timeAndReport(solutions, args, runs, id)