<p>Given two integer arrays <code>nums1</code> and <code>nums2</code>, return <em>an array of their <span data-keyword="array-intersection">intersection</span></em>. Each element in the result must be <strong>unique</strong> and you may return the result in <strong>any order</strong>.</p>

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

<pre>
<strong>Input:</strong> nums1 = [1,2,2,1], nums2 = [2,2]
<strong>Output:</strong> [2]
</pre>

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

<pre>
<strong>Input:</strong> nums1 = [4,9,5], nums2 = [9,4,9,8,4]
<strong>Output:</strong> [9,4]
<strong>Explanation:</strong> [4,9] is also accepted.
</pre>

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

<ul>
	<li><code>1 &lt;= nums1.length, nums2.length &lt;= 1000</code></li>
	<li><code>0 &lt;= nums1[i], nums2[i] &lt;= 1000</code></li>
</ul>

class Solution:
    def intersection(self, nums1: List[int], nums2: List[int]) -> List[int]:
        seen = {}
        result = []

        # mark values occurring in nums1
        for x in nums1:
          seen[x] = 1
          
        for x in nums2:
          # Check if x is in the dictionary and not in the result
          if x in seen and seen[x] == 1:
            result.append(x)
            seen[x] = 0

        # Return the result
        return result
16100