func findDifference(nums1 []int, nums2 []int) [][]int {
s1, s2 := make(map[int]bool), make(map[int]bool)
for _, v := range nums1 {
s1[v] = true
}
for _, v := range nums2 {
s2[v] = true
}
ans := make([][]int, 2)
for v := range s1 {
if !s2[v] {
ans[0] = append(ans[0], v)
}
}
for v := range s2 {
if !s1[v] {
ans[1] = append(ans[1], v)
}
}
return ans
}