Package g1501_1600.s1536_minimum_swaps_to_arrange_a_binary_grid

Class Solution

  • public class Solution
extends Object
    1536 - Minimum Swaps to Arrange a Binary Grid.

    Medium

    Given an n x n binary grid, in one step you can choose two adjacent rows of the grid and swap them.

    A grid is said to be valid if all the cells above the main diagonal are zeros.

    Return the minimum number of steps needed to make the grid valid, or -1 if the grid cannot be valid.

    The main diagonal of a grid is the diagonal that starts at cell (1, 1) and ends at cell (n, n).

    Example 1:

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

    Output: 3

    Example 2:

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

    Output: -1

    Explanation: All rows are similar, swaps have no effect on the grid.

    Example 3:

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

    Output: 0

    Constraints:

    • n == grid.length == grid[i].length
    • 1 <= n <= 200
    • grid[i][j] is either 0 or 1

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • minSwaps

        public int minSwaps​(int[][] grid)