添加了树的接口

tree/vbt/vbt.go

@@ -1,8 +1,10 @@
 package vbt
 
 import (
-	"github.com/474420502/focus/compare"
 	"github.com/davecgh/go-spew/spew"
+
+	"github.com/474420502/focus/compare"
+	"github.com/474420502/focus/tree"
 )
 
 type Node struct {
@@ -31,6 +33,10 @@ type Tree struct {
 	iter *Iterator
 }
 
+func assertImplementation() {
+	var _ tree.IBSTree = (*Tree)(nil)
+}
+
 func New(Compare compare.Compare) *Tree {
 	return &Tree{Compare: Compare, iter: NewIteratorWithCap(nil, 16)}
 }
@@ -231,6 +237,11 @@ func (tree *Tree) Remove(key interface{}) (interface{}, bool) {
 	return nil, false
 }
 
+func (tree *Tree) Clear() {
+	tree.root = nil
+	tree.iter = NewIteratorWithCap(nil, 16)
+}
+
 // Values 返回先序遍历的值
 func (tree *Tree) Values() []interface{} {
 	mszie := 0