Source: Two Steps Forward
Part 1: Create a 4x4 grid of rooms with doors
U
p,D
own,L
eft, andR
ight from each location. To determine if a door is currently open:
- Calculate
MD5(salt + sequence)
where sequence is a string containing any combination ofUDLR
depending on how you got to this room- The first four hex values represent the doors
U
p,D
own,L
eft, andR
ight respectively:bcdef
means open; anything else is closed
Find the shortest path from
(0, 0)
to(3, 3)
.