Package g0801_0900.s0840_magic_squares_in_grid

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    840 - Magic Squares In Grid.

    Medium

    A 3 x 3 magic square is a 3 x 3 grid filled with distinct numbers from 1 to 9 such that each row, column, and both diagonals all have the same sum.

    Given a row x col grid of integers, how many 3 x 3 "magic square" subgrids are there? (Each subgrid is contiguous).

    Example 1:

    Input: grid = [4,3,8,4,9,5,1,9,2,7,6,2]

    Output: 1

    Explanation: The following subgrid is a 3 x 3 magic square: while this one is not: In total, there is only one magic square inside the given grid.

    Example 2:

    Input: grid = [8]

    Output: 0

    Constraints:

    • row == grid.length

    • col == grid[i].length

    • 1 <= row, col <= 10

    • 0 <= grid[i][j] <= 15

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Integer numMagicSquaresInside(Array<IntArray> grid)

      • Methods inherited from class java.lang.Object

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