I have been doing this code Code Link

Problem is that when I iterating over keys to sort their vector, then sorting is not working properly. Test Case:- 3 4 3 4 3 3 3 7 5 5 1 1 5 3 3 3 7 3 4 1 5 5 3 1 5 3

Input is n and m, then two matrices of n*m

Any idea why? Thanks in advance:)