95 lines
2.8 KiB
JavaScript
95 lines
2.8 KiB
JavaScript
import fs from 'node:fs'
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function init(filename) {
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const data = fs.readFileSync(filename, { encoding: 'utf-8' }, data => data)
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const desertmap = new DesertMap(
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data.split('\n\n')[0].split(''),
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data.split('\n\n')[1]
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)
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desertmap.navigate_ghosts()
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}
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class DesertMap {
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instructions = []
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map = ""
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#route = []
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constructor(instructions, map) {
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this.instructions = instructions
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this.map = map
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this.#route = []
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this.steps = 0
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}
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setup() {
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const matches = [...this.map.matchAll(/(\w+) = \((\w+), (\w+)\)/gm)]
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matches.forEach(match => {
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this.#route.push({ from: match[1], L: match[2], R: match[3] })
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})
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}
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run(towards, from) {
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if (!this.steps && !from) {
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return this.#route.find(route => route.from === 'AAA')[towards]
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}
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return this.#route.find(route => route.from === from)[towards]
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}
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navigate_brute() {
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this.setup()
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let i = 0
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let start = this.#route.filter(route => route.from[2] === 'A')
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.map(route => route.from)
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while (i < this.instructions.length | true) {
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start = start.map(route => this.run(this.instructions[i], route))
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++this.steps
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if (start.filter(route => route[2] === 'Z').length === start.length) {
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console.log(this.steps)
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return true
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}
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i = this.instructions.length - i === 1 ? 0 : i + 1
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}
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console.log(this.steps + 1)
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}
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lcm(numbers) {
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function gcd(a, b) {
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if (b === 0) {
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return a;
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}
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return gcd(b, a % b);
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}
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return numbers.reduce((a, b) => a * b / gcd(a, b));
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}
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navigate_ghosts() {
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this.setup()
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let routes = this.#route.filter(route => route.from[2] === 'A')
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.map(route => route.from)
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let results = routes.map(route => {
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let i = 0
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let steps = 0
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while (i < this.instructions.length | true) {
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route = this.run(this.instructions[i], route)
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++steps
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if (route[2] === 'Z') { return steps }
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i = this.instructions.length - i === 1 ? 0 : i + 1
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}
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})
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console.log(`LCM of ${results.join(", ")}`)
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console.log(this.lcm(results))
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}
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navigate() {
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this.setup()
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let i = 0
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while (i < this.instructions.length | true) {
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let from = this.run(this.instructions[i], from)
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++this.steps
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console.log(i, from, this.steps)
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if (from === 'ZZZ') { return false }
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i = this.instructions.length - i === 1 ? 0 : i + 1
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}
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console.log(this.steps)
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}
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}
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init('input.txt') |