magic-squares-in-grid

magic-squares-in-grid


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?



Note: while a magic square can only contain numbers from 1 to 9, grid may contain numbers up to 15.



 


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


Report Page