def part1():
# Find the robot.
robot = Point(maze.maze[-1].find('^'), len(maze.maze)-1)
lastturn = robot
# Robot starts facing north.
facing = Point(0,-1)
crossings = set()
turns = []
while 1:
# If we are facing empty space, turn.
if maze[robot+facing] == '.':
if robot != lastturn:
turns.append( robot.dist(lastturn) )
if maze[robot+facing.left()] == '#':
facing = facing.left()
turns.append( "L" )
elif maze[robot+facing.right()] == '#':
facing = facing.right()
turns.append( "R" )
else:
# End of the scaffold.
break
lastturn = robot
robot += facing
# Otherwise, look for a crossing.
else:
if maze[robot+facing.left()] == '#' and maze[robot+facing.right()] == '#':
crossings.add( robot )
robot += facing
if TRACE:
print( robot )
# We return the set of crossings and the record of turns.
return crossings, turns
def part2():
ship = Point(0, 0)
waypt = Point(10, -1)
for ln in data:
direc = ln[0]
dist = int(ln[1:])
if direc in 'NESW':
waypt += deltas[direc] * dist
elif direc in 'L':
count = dist // 90
for i in range(count):
waypt = waypt.left()
elif direc in 'R':
count = dist // 90
for i in range(count):
waypt = waypt.right()
elif direc == 'F':
ship += waypt * dist
if DEBUG:
print(ln, ship, waypt)
return ship.mandist()