增加map集合示例

map_set/map.go

@@ -0,0 +1,36 @@
+package map_set
+
+import (
+	"sort"
+
+	"golang.org/x/exp/constraints"
+)
+
+func New[T comparable](slice ...T) map[T]struct{} {
+	mapSet := make(map[T]struct{}, len(slice))
+	for _, element := range slice {
+		mapSet[element] = struct{}{}
+	}
+	return mapSet
+}
+
+func In[T comparable](needle T, haystack map[T]struct{}) bool {
+	_, exists := haystack[needle]
+	return exists
+}
+
+func Keys[T comparable](mapSet map[T]struct{}) []T {
+	slice := make([]T, 0, len(mapSet))
+	for k := range mapSet {
+		slice = append(slice, k)
+	}
+	return slice
+}
+
+func Sort[T constraints.Ordered](mapSet map[T]struct{}) []T {
+	keys := Keys(mapSet)
+	sort.Slice(keys, func(i, j int) bool {
+		return keys[i] < keys[j]
+	})
+	return keys
+}

map_set/map_test.go

@@ -0,0 +1,16 @@
+package map_set
+
+import "testing"
+
+func TestMapSet(t *testing.T) {
+	mapSet := New(2, 3, 1, 5, 4)
+	res := In(3, mapSet)
+	if !res {
+		t.Error("In() error")
+	}
+
+	slice := Sort(mapSet)
+	if slice[0] != 1 || slice[1] != 2 || slice[2] != 3 || slice[3] != 4 || slice[4] != 5 {
+		t.Error("Sort() error")
+	}
+}