Pushpa_Agr_matrix_check_sum

[pushpaagr]

Space complexity O(1) constant, variable will be unchanged despite how long the matrix is.

Time complexity is n^2 as I have a loop within a loop.

[shrutivanw]

You could consider combining this and the next loop like so:

   length.times do
      sum_row += matrix[k][i] 
      sum_column += matrix[i][k]
      i += 1
   end

[shrutivanw]

Nice work! One minor comment added inline.