Question

COuld you suggest me the best algorithm to remove all zeros from given array in O(n) time and without external memory.
For example, 1 2 0 0 3 2 0 2 becomes 1 2 3 2 2

Answer 1

use two pointers – one for read and one for write.

• Iterate with the reader pointer on the array – if the element is zero increase only it.
• If the element is not zero – write it and increase both pointers.