input: Write a function to check if the diagonals in a grid are strictly increasing.
  assert increasing_diagonal([[1, 2, 3], [4, 5, 6], [7, 8, 9]]) == True
  assert increasing_diagonal([[1, 2, 3], [4, 3, 6], [7, 8, 9]]) == False
  assert increasing_diagonal([[1, 2, 3], [4, 5, 4], [7, 8, 9]]) == False
  assert increasing_diagonal([[1]]) == True
output: def increasing_diagonal(grid):
      n = len(grid)
      if n == 1:
          return True
      
      # Check main diagonal from top-left to bottom-right
      for i in range(n - 1):
          if grid[i][i] >= grid[i + 1][i + 1]:
              return False
      
      # Check anti-diagonal from top-right to bottom-left
      for i in range(n - 1):
          if grid[i][n - i - 1] >= grid[i + 1][n - i - 2]:
              return False
      
      return True