new file: .gitignore

new file:   LICENSE
new file:   README.md
new file:   compare/compare.go
new file:   for_test.go
new file:   heap/heap.go
new file:   heap/heap_test.go
new file:   interface.go
new file:   lastack/lastack.go
new file:   lastack/lastack_test.go
new file:   list/list.go
new file:   list/list_test.go
new file:   map/hashmap/hashmap.go
new file:   map/hashmap/hashmap_test.go
new file:   priority_list/iterator.go
new file:   priority_list/priority_list.go
new file:   priority_list/priority_list_test.go
new file:   priority_queue/iterator.go
new file:   priority_queue/priority_queue.go
new file:   priority_queue/priority_queue_test.go
new file:   priority_queue/vbt.go
new file:   priority_queue/vbt_test.go
new file:   priority_queuekey/iterator.go
new file:   priority_queuekey/priority_queuekey.go
new file:   priority_queuekey/priority_queuekey_test.go
new file:   priority_queuekey/vbt.go
new file:   priority_queuekey/vbt_test.go
new file:   set/hashset/hashset.go
new file:   set/hashset/hashset_test.go
new file:   set/treeset/treeset.go
new file:   set/treeset/treeset_test.go
new file:   sparse_array/array2/array2.go
new file:   sparse_array/array2/array2_test.go
new file:   sparse_array/array3/array3.go
new file:   sparse_array/array3/array3_test.go
new file:   sparse_array/arrayn/arrayn.go
new file:   sparse_array/arrayn/arrayn_test.go
new file:   stack/stack.go
new file:   stack/stack_test.go
new file:   tree/avl/avl.go
new file:   tree/avl/avl_test.go
new file:   tree/avl/iterator.go
new file:   tree/avldup/avldup.go
new file:   tree/avldup/avldup_test.go
new file:   tree/avldup/iterator.go
new file:   tree/avlkey/avlkey.go
new file:   tree/avlkey/avlkey_test.go
new file:   tree/avlkey/iterator.go
new file:   tree/avlkeydup/avlkeydup.go
new file:   tree/avlkeydup/avlkeydup_test.go
new file:   tree/avlkeydup/iterator.go
new file:   tree/vbt/iterator.go
new file:   tree/vbt/vbt.go
new file:   tree/vbt/vbt_test.go
new file:   tree/vbtkey/iterator.go
new file:   tree/vbtkey/vbtkey.go
new file:   tree/vbtkey/vbtkey_test.go

set/hashset/hashset.go

@@ -0,0 +1,80 @@
+package hashset
+
+import (
+	"fmt"
+	"strings"
+)
+
+var nullItem = struct{}{}
+
+// HashSet
+type HashSet struct {
+	hm map[interface{}]struct{}
+}
+
+// New
+func New() *HashSet {
+	return &HashSet{hm: make(map[interface{}]struct{})}
+}
+
+// Add
+func (set *HashSet) Add(items ...interface{}) {
+	for _, item := range items {
+		if _, ok := set.hm[item]; !ok {
+			set.hm[item] = nullItem
+		}
+	}
+}
+
+// Remove
+func (set *HashSet) Remove(items ...interface{}) {
+	for _, item := range items {
+		delete(set.hm, item)
+	}
+}
+
+// Values
+func (set *HashSet) Values() []interface{} {
+	values := make([]interface{}, set.Size())
+	count := 0
+	for item := range set.hm {
+		values[count] = item
+		count++
+	}
+	return values
+}
+
+// Contains
+func (set *HashSet) Contains(item interface{}) bool {
+	if _, contains := set.hm[item]; contains {
+		return true
+	}
+	return false
+}
+
+// Empty
+func (set *HashSet) Empty() bool {
+	return set.Size() == 0
+}
+
+// Clear
+func (set *HashSet) Clear() {
+	set.hm = make(map[interface{}]struct{})
+}
+
+// Size
+func (set *HashSet) Size() int {
+	return len(set.hm)
+}
+
+// String
+func (set *HashSet) String() string {
+	content := "["
+	items := []string{}
+	for k := range set.hm {
+		items = append(items, fmt.Sprintf("%v", k))
+	}
+	content += strings.Join(items, ",")
+	content += "]"
+	return content
+}

set/hashset/hashset_test.go

@@ -0,0 +1,54 @@
+package hashset
+
+import (
+	"bytes"
+	"encoding/gob"
+	"io/ioutil"
+	"log"
+	"testing"
+)
+
+func loadTestData() []int {
+	log.SetFlags(log.Lshortfile)
+
+	data, err := ioutil.ReadFile("../l.log")
+	if err != nil {
+		log.Println(err)
+	}
+	var l []int
+	decoder := gob.NewDecoder(bytes.NewReader(data))
+	decoder.Decode(&l)
+	return l
+}
+
+func TestAdd(t *testing.T) {
+
+	set := New()
+	for i := 0; i < 10; i++ {
+		set.Add(i)
+	}
+
+	if set.Size() != 10 {
+		t.Error("size is not equals to 10")
+	}
+}
+
+func TestRemove(t *testing.T) {
+	set := New()
+
+	for i := 0; i < 10; i++ {
+		set.Add(i)
+	}
+
+	for i := 0; i < 9; i++ {
+		set.Remove(i)
+	}
+
+	if set.Size() != 1 {
+		t.Error("size is not equals to 0")
+	}
+
+	if set.Values()[0] != 9 {
+		t.Error("remain is not 9")
+	}
+}