Advent of Code Day 12 (Part 2)

AoC2020_day12_p2.py

COMPASS = {
    "E": (+1, 0),
    "S": (0, +1),
    "W": (-1, 0),
    "N": (0, -1)
}

ship_pos = [0, 0]
waypoint = [10, -1]

nav_list = [(n[0], int(n[1:])) for n in open("input_12")]

for nav, value in nav_list:
    if nav in ("R", "L"):
        if nav == "L":
            value = -value
        value %= 360
        if value == 90:
            waypoint = [-waypoint[1], waypoint[0]]
        elif value == 180:
            waypoint = [-waypoint[0], -waypoint[1]]
        elif value == 270:
            waypoint = [waypoint[1], -waypoint[0]]

    if nav == "F":
        ship_pos[0] += waypoint[0] * value
        ship_pos[1] += waypoint[1] * value

    if nav in COMPASS.keys():
        waypoint[0] += COMPASS[nav][0] * value
        waypoint[1] += COMPASS[nav][1] * value

print(abs(ship_pos[0]) + abs(ship_pos[1]))

AoC2020_day12_p2_v2.py

COMPASS = {
    "E": (+1, 0), 
    "S": (0, +1),
    "W": (-1, 0),
    "N": (0, -1)
}

ship_pos = [0, 0]
waypoint = [10, -1]

nav_list = [(n[0], int(n[1:])) for n in open("input_12")]

for nav, value in nav_list:
    if nav in ("R", "L"):
        value = (nav == "L") and -value or value
        for q in range((value%360)//90):
            waypoint = [-waypoint[1], waypoint[0]]

    if nav == "F":
        ship_pos[0] += waypoint[0] * value
        ship_pos[1] += waypoint[1] * value

    if nav in COMPASS.keys():
        waypoint[0] += COMPASS[nav][0] * value
        waypoint[1] += COMPASS[nav][1] * value

print(abs(ship_pos[0]) + abs(ship_pos[1]))