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+# 840. Magic Squares In Grid
+
+"""
+a 3 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 contiguous 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.
+"""
+
+
+class Solution(object):
+ def numMagicSquaresInside(self, grid):
+ """
+ :type grid: List[List[int]]
+ :rtype: int
+ """
+
+ def isMagic(i, j):
+ s = "".join(
+ str(grid[i + x / 3][j + x % 3]) for x in [0, 1, 2, 5, 8, 7, 6, 3]
+ )
+ return grid[i][j] % 2 == 0 and (
+ s in "43816729" * 2 or s in "43816729"[::-1] * 2
+ )
+
+ return sum(
+ isMagic(i, j)
+ for i in range(len(grid) - 2)
+ for j in range(len(grid[0]) - 2)
+ if grid[i + 1][j + 1] == 5
+ )
+
+
+if __name__ == "__main__":
+ obj = Solution()
+ print(obj.numMagicSquaresInside(grid=[[4, 3, 8, 4], [9, 5, 1, 9], [2, 7, 6, 2]]))
+ print(obj.numMagicSquaresInside(grid=[[8]]))