Package g0701_0800.s0782_transform_to_chessboard

Class Solution

java.lang.Object
g0701_0800.s0782_transform_to_chessboard.Solution
public class Solution extends java.lang.Object
782 - Transform to Chessboard.

Hard

You are given an n x 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 moves to transform the board into a 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.

Example 1:

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.
 The first move swaps the first and second column.
 The second move swaps the second and third row.

Example 2:

Input: board = [[0,1],[1,0]]

Output: 0

Explanation: Also note that the board with 0 in the top left corner, is also a valid chessboard.

Example 3:

Input: board = [[1,0],[1,0]]

Output: -1

Explanation: No matter what sequence of moves you make, you cannot end with a valid chessboard.

Constraints:

  • n == board.length
  • n == board[i].length
  • 2 <= n <= 30
  • board[i][j] is either 0 or 1.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    movesToChessboard(int[][] board)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • movesToChessboard

      public int movesToChessboard(int[][] board)