advent of code 2020 day 2 part 2

day2_part2.js

const fs = require('fs')
const splitted = fs.readFileSync('./input.txt', 'utf-8').split(String.fromCharCode(0x0a))

function buildDictionary(splt) {
	let dict = []

	splt.forEach((el, i) => {
		if (!el.length) {
			return
		}

		let parts = el.split(String.fromCharCode(0x20))
		let minMaxPair = parts[0].split('-')

		dict.push({
			pivot: parts[1][0],
			min: Number.parseInt(minMaxPair[0]),
			max: Number.parseInt(minMaxPair[1]),
			target: parts[2]
		})
	})

	return dict
}

function solve(dict) {
	let numMatches = 0

	dict.forEach((el) => {
		if ((el.max - 1) > (el.target.length - 1)) {
			return
		}

		if (el.target.charAt(el.min - 1) === el.pivot && el.target.charAt(el.max - 1) === el.pivot) {
			return
		}

		if (el.target.charAt(el.min - 1) !== el.pivot && el.target.charAt(el.max - 1) !== el.pivot) {
			return
		}

		numMatches++
	})

	return numMatches
}

console.log(solve(buildDictionary(splitted)))