aoc-2021/day02/day02.ts

import { reduce } from "fp-ts/lib/Array";
import { pipe } from "fp-ts/lib/function";
import { moves } from "./input";
import { moves as testMoves } from "./input.test";

const position = pipe(
    moves,
    reduce([0, 0], ([horizontal, depth], [dir, len]) => {
        switch (dir) {
            case "forward":
                return [horizontal + len, depth];
            case "down":
                return [horizontal, depth + len];
            case "up":
                return [horizontal, depth - len];
            default:
                return [horizontal, depth];
        }
    })
);

console.log("the final position is", position);
console.log("the product of position coordinates is", position[0] * position[1]);

const positionWithAim = pipe(
    moves,
    reduce([0, 0, 0], ([aim, horizontal, depth], [dir, len]) => {
        switch (dir) {
            case "down":
                return [aim + len, horizontal, depth];
            case "up":
                return [aim - len, horizontal, depth];
            case "forward":
                return [aim, horizontal + len, depth + (aim * len)];
            default:
                return [aim, horizontal, depth];
        }
    })
);

console.log("the final position with aim is", positionWithAim);
console.log("the product of position coordinates is", positionWithAim[1] * positionWithAim[2]);