Function advent_of_code_2021::day_2::navigate

fn navigate(instructions: &Vec<(Direction, isize)>) -> (isize, isize)

This starts with the submarine at the origin, and moves using the following rules:

• Forward: Increase the horizontal position by the magnitude
• Up: Decrease the depth by the magnitude
• Down: Increase the depth by the magnitude

The final position after applying all the instructions in order is returned as a tuple (horizontal_position, depth)

Example from puzzle specification

let input = vec![
    (FORWARD, 5),
    (DOWN, 5),
    (FORWARD, 8),
    (UP, 3),
    (DOWN, 8),
    (FORWARD, 2),
]
assert_eq!(navigate(&input), (15, 10))