LeetCode： Duplicate Zeros

Question

Given a fixed length array arr of integers, duplicate each occurrence of zero, shifting the remaining elements to the right.

Note that elements beyond the length of the original array are not written.

Do the above modifications to the input array in place, do not return anything from your function.

Example 1:

Input: [1,0,2,3,0,4,5,0]

Output: null

Explanation: After calling your function, the input array is modified to: [1,0,0,2,3,0,0,4]

Example 2:

Input: [1,2,3]

Output: null

Explanation: After calling your function, the input array is modified to: [1,2,3]

Solution

def duplicate_zeros(arr)
  index = 0

  while index < arr.length-1
    if arr[index] == 0
      arr.insert(index, 0)
      arr.pop
      index += 2
    else
      index += 1
    end
  end
  arr
end