use std::collections::HashSet;

impl Solution {
    pub fn find_difference(nums1: Vec<i32>, nums2: Vec<i32>) -> Vec<Vec<i32>> {
        let nums1: HashSet<i32> = nums1.into_iter().collect();
        let nums2: HashSet<i32> = nums2.into_iter().collect();

        vec![
            (&nums1 - &nums2).into_iter().collect(),
            (&nums2 - &nums1).into_iter().collect(),
        ]
    }
}