2215-find-the-difference-of-two-arrays.ts

// Time Complexity: O(m + n), we check each element of nums1Set and nums2Set
// Space Complexity: O(m + n), where m and n are length sets in worst case.

function findDifference(nums1: number[], nums2: number[]): number[][] {
    const nums1Set: Set<number> = new Set(nums1);
    const nums2Set: Set<number> = new Set(nums2);

    const lst1: number[] = Array.from(nums1Set).filter(
        (num: number) => !nums2Set.has(num)
    );
    const lst2: number[] = Array.from(nums2Set).filter(
        (num: number) => !nums1Set.has(num)
    );

    return [lst1, lst2];
}