duplicate_zeroes.py

# Given a fixed-length integer array arr, 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 
# and do not return anything.

 

# Example 1:

# Input: arr = [1,0,2,3,0,4,5,0]
# Output: [1,0,0,2,3,0,0,4]
# Explanation: After calling your function, the input array is modified to: [1,0,0,2,3,0,0,4]
# Example 2:

# Input: arr = [1,2,3]
# Output: [1,2,3]
# Explanation: After calling your function, the input array is modified to: [1,2,3]
 

# Constraints:

# 1 <= arr.length <= 104
# 0 <= arr[i] <= 9

class Solution:
    def duplicateZeros(self, arr: List[int]) -> None:
        index = 0
        while index < len(arr):
            if arr[index] == 0:
                arr.insert(index, 0)
                arr.pop()
                index += 1
            index += 1