Answer
Original list : [2, 0, 4, 1]
Clean up list : [2, 4, 1]
Work Step by Step
Copy over algorithm creates another list and copies non zero element in that, at the end there will be two list the original list which remains unchanged and the copy list which have non zero elements.
Original list : [2, 0, 4, 1]
Clean up list : [2, 4, 1]
