Puzzle

  One day, Resty gets a very interesting puzzle. Eve said that she will make a cake for Resty if he solved this puzzle, so Resty asks you to help him to solve the puzzle as soon as possible.
  As the figure, the puzzle is a rectangle divided into 4 * 6 = 24 squares. Each cell has a color of white / black/ grey. There are exactly 8 cells of each color. Our purpose is to make the middle 8 cells(which are not on the edge) have the same color by minimal steps.

Each step, you could choose a row or a column to shift it for 1 bit. As following:

Now, given the puzzle, you should help Resty find the minimal steps he must use to solve it.

The first line is a number T, the number of test case.
Each case contains 4 lines, each line contains a 6-length string, describe a puzzle. B for black color, W for white and G for grey.

For each test, output on line in the Format “Case ID: ANS”, ANS should be the minimal number of steps to solve the puzzle.

3
GWGGWW
BBBBBW
GBBBGW
WGGGWW
GWGGWW
BWBBBB
GBBBGW
WGGGWW
WWWWWW
BGGGGB
WGGGGW
BBBBBB

Case 1: 2
Case 2: 3
Case 3: 0

Resty

HDOJ Monthly Contest – 2010.01.02