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Diffstat (limited to 'transform_to_chessboard.py')
-rw-r--r-- | transform_to_chessboard.py | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/transform_to_chessboard.py b/transform_to_chessboard.py new file mode 100644 index 0000000..e78edff --- /dev/null +++ b/transform_to_chessboard.py @@ -0,0 +1,50 @@ +# 782. Transform to Chessboard + +""" +you are given an 'n n' binary grid 'board'. in each move, you can swap any +two rows with each other, or any two columns with each other. return the +minimum number of rwos to transform the board intoa chessboard board. if the +task is impossible, return -1. a chessboard board is a board where no 0's and +no 1's are 4-directionally adjacent +""" + + +class Solution(object): + def movesToChessboard(self, board): + """ + :type board: List[List[int]] + :rtype: int + """ + n = len(board) + if any( + board[0][0] ^ board[i][0] ^ board[0][j] ^ board[i][j] + for i in range(n) + for j in range(n) + ): + return -1 + if not n / 2 <= sum(board[0]) <= (n + 1) / 2: + return -1 + if not n / 2 <= sum(board[i][0] for i in range(n)) <= (n + 1) / 2: + return -1 + col = sum(board[0][i] == i % 2 for i in range(n)) + row = sum(board[i][0] == i % 2 for i in range(n)) + if n % 2: + if col % 2: + col = n - col + if row % 2: + row = n - row + else: + col = min(n - col, col) + row = min(n - row, row) + return (col + row) / 2 + + +if __name__ == "__main__": + obj = Solution() + print( + obj.movesToChessboard( + board=[[0, 1, 1, 0], [0, 1, 1, 0], [1, 0, 0, 1], [1, 0, 0, 1]] + ) + ) + print(obj.movesToChessboard(board=[[0, 1], [1, 0]])) + print(obj.movesToChessboard(board=[[1, 0], [1, 0]])) |