Duplicate Zeros

Description

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 <= arr.length <= 10000

• 0 <= arr[i] <= 9

Code

// 从下标i开始将数组整体向后移动一格
public void moveFormI(int[] arr, int i) {
    if (arr.length - 1 - i >= 0) {
        System.arraycopy(arr, i, arr, i + 1, arr.length - 1 - i);
    }
}

public void duplicateZeros(int[] arr) {
    for (int i = 0; i < arr.length - 1; i++) {
        if (arr[i] == 0) {
            moveFormI(arr, i + 1);
            arr[i + 1] = arr[i];
            i++;
        }
    }
}