Duplicate Zeros
<p>Given a fixed-length integer array <code>arr</code>, duplicate each occurrence of zero, shifting the remaining elements to the right.</p>

<p><strong>Note</strong> 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.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> arr = [1,0,2,3,0,4,5,0]
<strong>Output:</strong> [1,0,0,2,3,0,0,4]
<strong>Explanation:</strong> After calling your function, the input array is modified to: [1,0,0,2,3,0,0,4]
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> arr = [1,2,3]
<strong>Output:</strong> [1,2,3]
<strong>Explanation:</strong> After calling your function, the input array is modified to: [1,2,3]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= arr.length &lt;= 10<sup>4</sup></code></li>
	<li><code>0 &lt;= arr[i] &lt;= 9</code></li>
</ul>
Array; Two Pointers
void duplicateZeros(int* arr, int arrSize) {
    int i = 0;
    int j = 0;
    while (j < arrSize) {
        if (arr[i] == 0) {
            j++;
        }
        i++;
        j++;
    }
    i--;
    j--;
    while (i >= 0) {
        if (arr[i] == 0) {
            if (j < arrSize) {
                arr[j] = arr[i];
            }
            j--;
        }
        arr[j] = arr[i];
        i--;
        j--;
    }
}