An N x N board contains only 0s and 1s. In each move,
you can swap any 2 rows with each other, or any 2 columns with each other.
What is the minimum number of moves to transform the board into a "chessboard" - a
board where no 0s and no 1s are 4-directionally adjacent? If the
task is impossible, return -1.
Examples: Input: board = [[0,1,1,0],[0,1,1,0],[1,0,0,1],[1,0,0,1]] Output: 2 Explanation: One potential sequence of moves is shown below, from left to right: 0110 1010 1010 0110 --> 1010 --> 0101 1001 0101 1010 1001 0101 0101 The first move swaps the first and second column. The second move swaps the second and third row. Input: board = [[0, 1], [1, 0]] Output: 0 Explanation: Also note that the board with 0 in the top left corner, 01 10 is also a valid chessboard. Input: board = [[1, 0], [1, 0]] Output: -1 Explanation: No matter what sequence of moves you make, you cannot end with a valid chessboard.
Note:
board will have the same number of rows and columns, a number in the range
[2, 30].
board[i][j] will be only 0s or 1s.