1089. Duplicate Zeros

Problem

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]

Note:

1. 1 <= arr.length <= 10000
2. 0 <= arr[i] <= 9

Problem Summary

Given a fixed-length integer array arr, duplicate each zero that appears in the array and shift the remaining elements to the right. Note: Do not write elements beyond the length of the array. Requirement: Modify the input array in place as described above, and do not return anything from the function.

Solution Approach

• Given a fixed-length array, duplicate every element whose value is 0 to the next position, shift the following elements to the right, and discard the part that exceeds the array length.
• This is an easy problem. Follow the problem statement and use append and slice operations.

Code

package leetcode

func duplicateZeros(arr []int) {
	for i := 0; i < len(arr); i++ {
		if arr[i] == 0 && i+1 < len(arr) {
			arr = append(arr[:i+1], arr[i:len(arr)-1]...)
			i++
		}
	}
}