Remove all zeros from array O(n), no extra memory

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.