Well Mr. Rifat, this is nice coding but does not fulfill the purpose. I dont know how did this solution checked as correct. Let me tell you about Toeplitz Matrix. A matrix in which all elements of main diagonal are equal and elements of other sub-diagonals parallel to main diagonal are equal. plz check this eg:a=[2 0 7 8 9;3 2 0 7 8;6 3 2 0 7;4 6 3 2 0;1 4 6 3 2]. Your coding still gives true even for non-toeplitz matrix. I'll check my reference solution again. Thanks for your time.

Sorry... I misread the definition. I thought it was only the main diagonal. I will submit another solution. Anyway.. your test suite should contain matrices to prevent such cases.