aoc24/solutions/01.ts

import { solvables } from "../main.ts";

import type { Solvable } from "../solvable.ts";
import { readInput } from "../utils.ts";

class DayOne implements Solvable {
    input = readInput('01')

    public part1(): DayOne {
        const vals = this.input
            .trim()
            .split("\n")
            .map(line => line.split('   ').map(col => Number.parseInt(col)))
        const left  = vals.map(line => line[0]).sort()
        const right = vals.map(line => line[1]).sort()
        
        const diff: number[] = []
        left.forEach((left, idx) => {
            diff.push(Math.abs(left - right[idx]))
        })
        
        const result = diff.reduce((prev, curr) => prev + curr)
        console.log(result)
        return this
    }

    public part2(): DayOne {
            const vals = this.input.trim().split("\n").map(line => line.split('   '))
            const left  = vals.map(line => Number.parseInt(line[0])).sort()
            const right = vals.map(line => Number.parseInt(line[1])).sort()

            const countedOccurences: Map<number, number> = new Map()
            left.forEach(left_val => countedOccurences.set(left_val, right.filter(right_val => left_val === right_val).length))
            const result = countedOccurences
                .entries()
                .map(([left_val, occurences]) => left_val * occurences)
                .reduce((prev, curr) => prev + curr)
            console.log(result)
        return this
    }
}

solvables.push(new DayOne())