[leetcode] problem 349 – intersection of two arrays

Given two arrays, write a function to compute their intersection.

Example

No.1

Input: nums1 = [1,2,2,1], nums2 = [2,2]

Output: [2]

No.2

Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4]

Output: [9,4]

Note

  • Each element in the result must be unique.
  • The result can be in any order.

Code

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public int[] intersection(int[] nums1, int[] nums2) {
Set<Integer> set = new HashSet<>();
List<Integer> list = new ArrayList<>();

for (int num : nums1)
set.add(num);

for (int num : nums2) {
if (!set.contains(num))
continue;

list.add(num);
set.remove(num);
}

int[] result = new int[list.size()];

for (int i = 0; i < result.length; i++)
result[i] = list.get(i);

return result;
}