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(), ] } }