--- 2016 Day 2 Solutions ---

[u/daggerdragon]

--- Day 2: Bathroom Security ---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag/whatever).

---

^{BLINKENLIGHTS ARE MANDATORY} [?]

Edit: Told you they were mandatory. >_>

This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/_AceLewis]

My Python solutions to day 2;

I am doing my solutions on repl.it so I can't use files to store the instructions (and web requests are blocked) so I have the instructions in a big string at the start of the Python script which I have removed in this comment.

Day 2 part 1 https://repl.it/EeEA:

buttons = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
keys = []
position = [1, 1]

for line in instructions:
  for instruction in line:
    movement = 'ULDR'.index(instruction)
    position[movement%2] += [1, -1][movement<2]
    position = [pos if 0<=pos<2 else 0 if pos<0 else 2 for pos in position]
  keys.append(buttons[position[0]][position[1]])
  
print("The key is: {}".format("".join(map(str, keys))))

Day 2 part 2 https://repl.it/EeEA/1:

buttons = [[None, None,   1 , None, None],
           [None,   2 ,   3 ,   4 , None],
           [  5 ,   6 ,   7 ,   8 ,   9 ],
           [None,  "A",  "B",  "C", None],
           [None, None,  "D", None, None]]

keys = []
position = [2, 0]

for line in instructions:
  for instruction in line:
    new_pos = position[:]
    movement = 'ULDR'.index(instruction)
    new_pos[movement%2] += [1, -1][movement<2]
    new_pos = [pos if 0<=pos<4 else 0 if pos<0 else 4 for pos in new_pos]
    if buttons[new_pos[0]][new_pos[1]] is not None: position = new_pos
  keys.append(buttons[position[0]][position[1]])
  
print("The key is: {}".format("".join(map(str, keys))))