Google·Software Engineer·Technical Phone Screen
- Given two strings of equal length over the characters R, L, and underscore, where R can only slide right into empty squares and L can only slide left into empty squares, determine whether some sequence of moves can transform the first string into the second.
- Extend your solution to handle a new immovable wall character. Walls cannot be crossed by any piece, never move themselves, and must appear at identical positions in both strings. The reachability check now applies independently within each segment between walls.
“The chess framing threw me for about thirty seconds before I realized what was actually being asked.”