Bitwise XOR of All Pairings
<p>You are given two <strong>0-indexed</strong> arrays, <code>nums1</code> and <code>nums2</code>, consisting of non-negative integers. Let there be another array, <code>nums3</code>, which contains the bitwise XOR of <strong>all pairings</strong> of integers between <code>nums1</code> and <code>nums2</code> (every integer in <code>nums1</code> is paired with every integer in <code>nums2</code> <strong>exactly once</strong>).</p>

<p>Return<em> the <strong>bitwise XOR</strong> of all integers in </em><code>nums3</code>.</p>

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

<pre>
<strong>Input:</strong> nums1 = [2,1,3], nums2 = [10,2,5,0]
<strong>Output:</strong> 13
<strong>Explanation:</strong>
A possible nums3 array is [8,0,7,2,11,3,4,1,9,1,6,3].
The bitwise XOR of all these numbers is 13, so we return 13.
</pre>

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

<pre>
<strong>Input:</strong> nums1 = [1,2], nums2 = [3,4]
<strong>Output:</strong> 0
<strong>Explanation:</strong>
All possible pairs of bitwise XORs are nums1[0] ^ nums2[0], nums1[0] ^ nums2[1], nums1[1] ^ nums2[0],
and nums1[1] ^ nums2[1].
Thus, one possible nums3 array is [2,5,1,6].
2 ^ 5 ^ 1 ^ 6 = 0, so we return 0.
</pre>

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

<ul>
	<li><code>1 &lt;= nums1.length, nums2.length &lt;= 10<sup>5</sup></code></li>
	<li><code>0 &lt;= nums1[i], nums2[j] &lt;= 10<sup>9</sup></code></li>
</ul>
Bit Manipulation; Brainteaser; Array
func xorAllNums(nums1 []int, nums2 []int) int {
	ans := 0
	if len(nums2)%2 == 1 {
		for _, v := range nums1 {
			ans ^= v
		}
	}
	if len(nums1)%2 == 1 {
		for _, v := range nums2 {
			ans ^= v
		}
	}
	return ans
}