LabyrinthDecoration | Topcoder Archive

Problem Statement

We are given a labyrinth as a rectangular matrix where '#' characters represent walls and spaces represent empty areas. We want to format it to look nicer using the following idea:

Empty areas will remain as spaces.
If a wall is neighbored directly above and below by walls (but not to the left or right), it will be represented as '|'.
If a wall is neighbored directly to the left and right by walls (but not above or below), it will be represented as '-'.
If a wall has no more than one neighboring wall, it will be represented as 'o' (the lowercase letter).
If a wall does not fall into one of the previous categories, it will be represented as '+'.

So, for example, if the input labyrinth is:

{"### #",
 "#   #",
 "# # #",
 "    #",
 "#####"}

The result will be:

{"+-o o",
 "|   |",
 "o o |",
 "    |",
 "o---+"}

Given the original labyrinth as a String[], return a String[] of the same dimensions containing the formatted labyrinth.

Definition

Class:: LabyrinthDecoration
Method:: decorate
Parameters:: String[]
Returns:: String[]
Method signature:: String[] decorate(String[] labyrinth)
(be sure your method is public)

Notes

Two cells are neighbors if and only if they share a side. This means inner cells have 4 neighbors, border cells have 3 neighbors and corner cells have 2 neighbors.

Constraints

labyrinth will have between 2 and 50 elements, inclusive.
Each element of labyrinth will have exactly N characters, where N is an integer between 2 and 50, inclusive.
Each character of each element of labyrinth will be either ' ' (a space) or '#'.

Examples

{"### #",
 "#   #",
 "# # #",
 "    #",
 "#####"}

Returns: {"+-o o", "|   |", "o o |", "    |", "o---+" }

The example from the problem statement.

{"####",
 "####",
 "####",
 "####"}

Returns: {"++++", "++++", "++++", "++++" }

It's not necessary for the input to represent a true "labyrinth".

{"#########",
 "# #     #",
 "    ### #",
 "### #   #",
 "#   # ###",
 "# ### #  ",
 "# #     #",
 "#########"}

Returns: {"+-+-----+", "o o     |", "    +-o |", "+-o |   |", "|   | +-+", "| +-+ o  ", "| |     o", "+-+-----+" }

{"  # ## # # #  # #   ",
 "     ############ # ",
 " #### # # #  # # ###",
 "   # ####### #  ####"}

Returns: {"  o o+ o o o  o o   ", "     +++++++-++++ o ", " o-+o | | |  | o +++", "   o o+-+-+o o  o+++" }

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