aoc2020/day12.py
Stefan Harmuth 1f61c4b97d day12
2020-12-12 06:34:48 +01:00

80 lines
1.7 KiB
Python

import aoclib
DAY = 12
TEST_SOLUTION_PART1 = 25
TEST_SOLUTION_PART2 = 286
FACING = ['N', 'E', 'S', 'W']
def move(instruction, x, y, j):
where = instruction[0]
dist = int(instruction[1:])
if where == 'F':
where = FACING[j]
if where == 'N':
y -= dist
elif where == 'S':
y += dist
elif where == 'E':
x += dist
elif where == 'W':
x -= dist
elif where == 'R':
j = (j + int(dist / 90)) % 4
elif where == 'L':
j = (j - int(dist / 90)) % 4
return x, y, j
def part1(test_mode=False):
my_input = aoclib.getInputAsArray(day=DAY, test=test_mode)
posX = 0
posY = 0
face = 1
for direction in my_input:
posX, posY, face = move(direction, posX, posY, face)
return abs(posX) + abs(posY)
def moveWaypoint(inst, sx, sy, wx, wy):
where = inst[0]
dist = int(inst[1:])
if where == 'F':
sx += wx * dist
sy += wy * dist
if where == 'N':
wy -= dist
elif where == 'S':
wy += dist
elif where == 'E':
wx += dist
elif where == 'W':
wx -= dist
elif where == 'R':
for i in range(int(dist / 90)):
wx, wy = -wy, wx
elif where == 'L':
for i in range(int(dist / 90)):
wx, wy = wy, -wx
return sx, sy, wx, wy
def part2(test_mode=False):
my_input = aoclib.getInputAsArray(day=DAY, test=test_mode)
posShipX = 0
posShipY = 0
posWaypointX = 10
posWaypointY = -1
for direction in my_input:
posShipX, posShipY, posWaypointX, posWaypointY = moveWaypoint(direction, posShipX, posShipY, posWaypointX, posWaypointY)
return abs(posShipX) + abs(posShipY)