You have an uncompleted rectangular grid and have to colour all the cells, either black or white, with two constraints:
- No three consecutives cells, horizontally or vertically, are all black or all white.
- Each row and column contains as many black cells as white cells.
The grid will be represented by a tuple of strings. Empty cells are represented by '.', black cells by 'B' and white cells by 'W'.
('......', ('BBWWBW', '..B...', 'BWBWBW', 'W.B.W.', 'WWBBWB', '......', 'BBWWBW', 'W...W.', 'WBWBWB', 'WW..W.') 'WWBBWB')
Input: A tuple of strings.
Output: A tuple/list/iterable of strings.
unruly(('......', '..B...', 'W.B.W.', '......', 'W...W.', 'WW..W.')) == ('BBWWBW', 'BWBWBW', 'WWBBWB', 'BBWWBW', 'WBWBWB', 'WWBBWB')
- Given puzzles are solvable.
- You can solve all puzzles without making any guesses.
- 6 ≤ len(grid) ≤ 40 and 6 ≤ len(grid) ≤ 30.
- all(len(row) == len(grid) for row in grid).