update 349.md 😎

book.leetcode/docs/easy/349.md

@@ -36,21 +36,19 @@ func intersection(nums1 []int, nums2 []int) []int {
 	}
 
 	var (
-		m1, m2 = make(map[int]interface{}), make(map[int]interface{})
+		set = make(map[int]struct{}, 0)
+		ret = make([]int, 0)
 	)
 
+	// 重复的会直接覆盖
 	for _, each := range nums1 {
-		m1[each] = nil
+		set[each] = struct{}{}
 	}
 
 	for _, each := range nums2 {
-		m2[each] = nil
-	}
-
-	ret := make([]int, 0)
-	for key, _ := range m1 {
-		if _, ok := m2[key]; ok {
-			ret = append(ret, key)
+		if _, ok := set[each]; ok {
+			ret = append(ret, each)
+			delete(set, each)
 		}
 	}