leetcode-go/leetcode/easy/349.intersection-of-two-arrays.go

func intersection(nums1 []int, nums2 []int) (res []int) {
	m := make(map[int]int)
	for _, n := range nums1 {
		m[n] |= 1
	}
	for _, n := range nums2 {
		m[n] |= 2
	}
	for k, v := range m {
		if v == 3 {
			res = append(res, k)
		}
	}
	return
}