02 Dive.js

/** Advent of Code 2021
 * Challenge Day 2: Dive
 * https://adventofcode.com/2021/day/2
 * */

const INPUT = `forward 6
down 3
forward 8
down 5
forward 9
down 2
up 9
down 9
forward 8
down 3
down 8
forward 2
down 1
up 3
up 6
up 9
down 7
up 7
down 1
forward 7
down 7
up 4
down 2
forward 8
up 3
up 1
down 1
down 6
up 2
down 5
forward 4
down 5
down 3
forward 4
down 3
up 8
forward 1
up 9
forward 2
up 7
down 2
down 9
down 1
down 6
down 8
down 6
down 1
down 1
down 9
down 9
down 2
forward 9
down 1
forward 4
down 2
forward 6
down 8
forward 4
forward 8
forward 4
forward 4
up 4
up 9
down 6
forward 2
forward 5
down 2
forward 1
down 9
forward 2
down 8
down 2
forward 5
down 7
forward 7
down 4
up 3
down 9
forward 3
down 7
up 4
down 5
down 4
forward 8
down 2
down 2
forward 9
down 9
down 5
down 1
down 5
forward 5
down 1
up 7
down 2
forward 7
forward 6
forward 5
forward 4
down 3
forward 9
up 1
down 1
up 8
down 4
down 7
forward 2
down 1
up 9
up 3
down 4
down 1
down 9
down 4
forward 4
forward 7
down 7
down 1
up 6
forward 8
down 8
forward 2
down 4
up 4
forward 3
down 1
up 8
up 2
forward 3
forward 5
forward 7
down 5
up 2
down 6
forward 9
forward 3
down 1
forward 7
up 1
down 4
up 2
forward 5
down 1
forward 2
down 3
forward 9
down 1
down 6
down 7
up 9
down 5
down 1
forward 5
forward 7
down 6
forward 1
down 3
forward 3
forward 1
down 7
forward 9
forward 7
forward 4
up 1
down 8
up 8
down 3
forward 9
up 2
down 4
down 4
down 3
forward 7
forward 3
down 5
up 4
up 7
down 6
forward 2
down 2
down 9
down 9
down 7
down 7
forward 5
forward 8
up 2
forward 9
forward 5
down 2
up 6
down 2
up 2
down 6
down 3
down 2
down 3
down 9
forward 6
up 9
down 3
forward 9
forward 4
forward 1
down 3
down 4
forward 8
forward 4
down 7
forward 9
forward 2
forward 9
down 2
down 3
down 1
down 6
forward 5
down 3
forward 1
down 3
forward 7
down 3
forward 3
up 2
up 8
down 2
down 3
down 7
forward 6
forward 7
up 5
forward 4
forward 6
down 1
forward 1
forward 9
down 2
down 8
forward 6
down 8
down 5
forward 9
forward 3
down 6
forward 3
forward 1
up 7
down 2
down 9
up 6
forward 7
down 9
up 8
forward 5
forward 2
forward 9
down 3
up 7
forward 7
down 4
up 6
up 5
forward 6
forward 2
down 9
forward 9
forward 3
down 4
forward 5
forward 4
forward 4
down 8
forward 4
forward 2
up 8
down 8
forward 6
up 4
down 7
forward 8
up 9
forward 3
forward 5
forward 8
down 5
up 6
up 6
down 5
forward 2
down 3
up 1
down 8
forward 3
down 4
up 9
forward 8
forward 5
forward 2
forward 6
forward 8
up 5
forward 5
down 2
down 4
down 8
forward 3
up 9
down 1
down 9
forward 7
forward 9
down 4
down 2
forward 3
down 1
forward 2
down 2
down 5
forward 2
forward 3
forward 9
down 2
forward 3
forward 9
forward 6
forward 7
down 6
forward 5
up 7
forward 6
up 1
down 7
down 6
down 3
down 7
forward 2
forward 8
forward 3
down 3
forward 7
down 3
up 8
forward 1
down 5
down 9
down 6
forward 1
forward 1
down 1
down 1
forward 8
forward 7
forward 1
up 2
down 4
up 7
down 3
up 8
up 7
forward 3
up 9
down 5
forward 4
down 6
up 8
forward 6
forward 7
down 1
up 7
down 9
down 9
up 9
forward 7
down 6
down 4
down 6
down 7
down 7
up 7
down 4
up 7
forward 1
down 8
down 3
down 2
forward 9
up 7
down 1
down 2
forward 1
forward 5
down 7
up 4
down 7
down 4
down 5
up 8
down 6
down 2
down 4
up 5
down 8
down 3
down 9
forward 6
forward 5
down 1
down 3
down 2
down 3
forward 8
forward 4
forward 6
forward 9
up 1
forward 6
forward 8
down 2
down 1
forward 4
forward 2
forward 3
forward 2
forward 5
forward 2
forward 7
down 5
forward 2
forward 3
forward 9
down 3
down 4
down 7
down 9
down 5
forward 5
down 4
down 8
up 3
forward 1
forward 2
forward 6
up 2
down 9
down 8
up 8
up 3
forward 2
down 6
forward 9
down 3
down 3
forward 7
down 5
forward 2
down 4
down 1
forward 1
down 5
up 4
down 2
forward 8
down 9
down 5
up 4
forward 9
down 3
down 8
forward 8
forward 9
forward 3
up 5
forward 6
down 7
forward 5
down 4
down 9
down 1
up 4
down 8
forward 4
up 4
forward 4
forward 8
forward 3
forward 6
down 9
forward 5
up 4
forward 8
forward 2
down 2
down 1
up 3
forward 5
down 3
down 6
forward 7
down 8
down 1
forward 9
down 8
forward 7
forward 7
forward 7
up 9
up 5
forward 5
forward 2
down 4
up 8
up 7
forward 5
forward 3
forward 7
up 1
down 2
up 1
forward 3
up 8
down 3
forward 1
forward 5
forward 2
forward 5
down 8
up 1
forward 9
down 3
down 7
up 5
down 5
down 1
down 4
down 6
up 9
forward 5
forward 3
down 8
down 7
forward 3
down 9
forward 8
down 3
up 2
up 7
forward 3
down 9
down 5
down 9
up 6
down 9
down 1
down 1
up 4
up 5
up 6
forward 5
down 3
up 1
forward 9
forward 8
forward 8
forward 3
forward 5
forward 8
forward 1
down 8
up 7
down 3
forward 9
forward 1
up 8
down 7
up 4
down 2
down 5
forward 3
down 5
forward 8
forward 4
down 6
up 7
up 7
forward 8
down 6
down 8
down 9
forward 8
forward 1
forward 6
up 2
up 1
up 8
forward 8
forward 1
forward 4
forward 7
forward 2
down 7
down 8
up 5
up 4
up 4
up 7
forward 3
down 2
up 5
down 8
forward 6
up 9
forward 1
down 2
forward 7
down 4
down 6
down 3
down 7
down 9
down 3
forward 1
forward 5
down 2
down 6
up 7
up 2
up 3
up 5
forward 9
down 6
up 1
down 1
forward 3
forward 5
up 8
forward 5
forward 9
up 5
up 4
down 6
up 8
down 8
down 7
down 2
down 6
up 1
up 1
forward 8
down 4
up 3
down 2
down 1
forward 2
down 4
down 6
forward 2
up 8
forward 9
up 1
up 4
forward 2
down 9
down 4
forward 7
forward 6
forward 2
forward 2
forward 5
forward 6
down 3
forward 1
up 9
forward 2
down 3
down 1
down 3
up 9
forward 5
up 5
up 7
down 5
down 4
down 9
down 3
down 3
down 9
down 4
down 3
down 9
forward 9
down 1
down 6
down 7
down 7
down 5
down 8
down 5
forward 1
forward 3
up 1
forward 2
up 5
up 8
down 1
up 8
up 6
up 4
up 1
forward 3
forward 2
forward 4
up 3
down 6
down 1
down 6
up 8
up 7
forward 8
down 9
down 3
forward 2
forward 8
forward 8
down 1
forward 9
down 2
down 3
down 9
down 2
forward 8
down 2
down 6
forward 8
forward 1
up 1
forward 3
down 5
down 6
down 5
down 4
forward 6
forward 3
down 7
down 8
down 7
up 7
down 9
down 8
forward 6
down 1
forward 8
forward 9
up 4
down 1
forward 1
forward 9
down 4
down 2
forward 4
down 5
forward 4
down 7
forward 6
down 3
forward 3
forward 2
forward 7
down 2
forward 2
down 3
up 9
forward 4
forward 1
forward 8
forward 8
forward 6
forward 7
up 8
down 4
up 6
forward 3
up 8
forward 3
forward 1
forward 3
forward 9
up 2
up 5
forward 8
forward 6
forward 6
forward 4
down 6
forward 7
forward 3
forward 2
forward 2
forward 6
forward 5
down 7
up 1
forward 5
up 1
up 9
forward 5
up 3
forward 1
down 2
up 2
down 4
forward 7
forward 4
forward 1
down 1
up 4
down 4
up 2
up 5
down 5
forward 7
up 1
down 6
up 4
forward 3
forward 8
down 6
forward 4
down 2
down 3
down 5
down 4
down 9
up 4
forward 5
up 1
up 2
forward 7
forward 2
up 1
down 8
forward 4
forward 4
up 8
down 3
down 4
up 7
down 8
down 6
down 2
down 3
forward 9
forward 7
forward 6
down 2
down 7
forward 5
forward 2
up 5
down 5
forward 5
down 3
down 1
forward 4
forward 3
down 2
up 1
down 3
down 5
forward 6
forward 5
up 5
down 3
forward 8
down 9
up 4
up 4
down 8
forward 5
down 7
down 3
up 1
down 4
down 5
forward 4
forward 2
forward 4
up 9
down 5
forward 4
forward 6
forward 9
forward 7
forward 5
forward 6
up 4
forward 8
down 4
forward 4
forward 6
up 8
down 4
forward 3
down 8
forward 4
down 9
forward 5
down 4
up 8
forward 2
down 6
up 3
down 5
down 1
down 6
down 9
forward 9
down 1
down 5
up 8
forward 5
down 6
down 9
forward 1
down 6
down 8
down 1
down 2
down 1
forward 5
up 7
forward 5
down 2
down 4
down 1
forward 7
down 7
down 8
forward 4
forward 7
down 2
down 3
forward 2
up 9
down 4
down 5
forward 4
forward 4
forward 6
down 5
forward 8
down 9
forward 8
down 7
up 7
forward 9
up 1
forward 4
up 3
down 2
down 4
down 5
forward 2
forward 8
up 3
up 1
down 1
forward 7
forward 9
forward 6
up 1
down 2
forward 1
up 5
forward 3
down 7
down 6
forward 9
forward 6
forward 3
forward 8
down 2
down 7
forward 1
down 6
up 3
down 6
down 9
up 2
forward 8
forward 1
down 9
forward 8
forward 8
down 3
up 9
down 6
up 3
forward 3
forward 5
forward 7
`;

// convert input into a nested array containing instructions and numbers
// with help from https://stackoverflow.com/a/34971243/5227705
var course = JSON.parse('[[' + INPUT.replace(/([a-zA-Z]+)/g, '"$1"').replace(/ /g, ',').replaceAll(/\n/g, '],[') + `]]`);

/** Part 1 */

var hor_pos = 0;
var depth = 0;

// iterate through nested array and adjust values based on each step
for (var i=0; i<course.length; i++) {
    switch (course[i][0]) {
        case "forward":
            hor_pos = hor_pos + course[i][1];
            break;
        case "down":
            depth = depth + course[i][1];
            break;
        case "up":
            depth = depth - course[i][1];
            break;
    }
}

var final_pos = hor_pos * depth;
console.log(final_pos);

/** Part 2 */

hor_pos = 0;
depth = 0;
var aim = 0;

// iterate through nested array and adjust values based on each step
for (var i=0; i<course.length; i++) {
    switch (course[i][0]) {
        case "forward":
            hor_pos = hor_pos + course[i][1];
            depth = depth + (aim * course[i][1]);
            break;
        case "down":
            aim = aim + course[i][1];
            break;
        case "up":
            aim = aim - course[i][1];
            break;
    }
}

var final_pos2 = hor_pos * depth;
console.log(final_pos2);