diff --git a/list/array_list/array_list.go b/list/array_list/array_list.go
index 3dc18ca..5ad1c23 100644
--- a/list/array_list/array_list.go
+++ b/list/array_list/array_list.go
@@ -4,6 +4,7 @@ import (
 	"log"
 
 	"github.com/474420502/focus/list"
+	"github.com/davecgh/go-spew/spew"
 )
 
 type ArrayList struct {
@@ -34,6 +35,7 @@ func New() *ArrayList {
 	l.data = make([]interface{}, initCap, initCap)
 	l.tidx = initCap / 2
 	l.hidx = l.tidx - 1
+	// l.shrinkSize = listMinLimit
 	return l
 }
 
@@ -67,15 +69,19 @@ func (l *ArrayList) shrink() {
 	}
 
 	if l.size <= l.shrinkSize {
-		nSize := l.shrinkSize - l.shrinkSize>>1
+		lcap := uint(len(l.data))
+		nSize := lcap - lcap>>2
 		temp := make([]interface{}, nSize, nSize)
 
-		ghidx := l.size / 2
+		ghidx := l.size >> 2
 		gtidx := ghidx + l.size + 1
 		copy(temp[ghidx+1:], l.data[l.hidx+1:l.tidx])
 		l.data = temp
 		l.hidx = ghidx
 		l.tidx = gtidx
+
+		// l.shrinkSize = l.shrinkSize - lcap>>2
+		l.shrinkSize = l.size - l.size>>2
 	}
 
 }
@@ -98,6 +104,7 @@ func (l *ArrayList) growth() {
 	l.hidx = ghidx
 	l.tidx = gtidx
 
+	l.shrinkSize = l.size - l.size>>2
 }
 
 func (l *ArrayList) Push(value interface{}) {
@@ -140,6 +147,7 @@ func (l *ArrayList) PopFront() (result interface{}, found bool) {
 	if l.size != 0 {
 		l.size--
 		l.hidx++
+		l.shrink()
 		return l.data[l.hidx], true
 	}
 	return nil, false
@@ -149,25 +157,32 @@ func (l *ArrayList) PopBack() (result interface{}, found bool) {
 	if l.size != 0 {
 		l.size--
 		l.tidx--
+		l.shrink()
 		return l.data[l.tidx], true
 	}
 	return nil, false
 }
 
-func (l *ArrayList) Index(idx uint) (interface{}, bool) {
-	if idx < l.size {
-		return l.data[idx+l.hidx+1], true
+func (l *ArrayList) Index(idx int) (interface{}, bool) {
+	var uidx uint = (uint)(idx)
+	if uidx < l.size {
+		return l.data[uidx+l.hidx+1], true
 	}
 	return nil, false
 }
 
-func (l *ArrayList) Remove(idx uint) (result interface{}, isfound bool) {
+func (l *ArrayList) Remove(idx int) (result interface{}, isfound bool) {
 
-	if idx >= l.size {
+	if idx < 0 {
 		return nil, false
 	}
 
-	offset := l.hidx + 1 + idx
+	var uidx = (uint)(idx)
+	if uidx >= l.size {
+		return nil, false
+	}
+
+	offset := l.hidx + 1 + uidx
 
 	isfound = true
 	result = l.data[offset]
@@ -210,6 +225,10 @@ func (l *ArrayList) Values() []interface{} {
 	return newElements
 }
 
+func (l *ArrayList) String() string {
+	return spew.Sprint(l.Values())
+}
+
 func (l *ArrayList) Traversal(every func(interface{}) bool) {
 	for i := uint(0); i < l.size; i++ {
 		if !every(l.data[i+l.hidx+1]) {
diff --git a/list/array_list/array_list_test.go b/list/array_list/array_list_test.go
index 2785d66..2cc7cc7 100644
--- a/list/array_list/array_list_test.go
+++ b/list/array_list/array_list_test.go
@@ -1,10 +1,6 @@
 package arraylist
 
 import (
-	"bytes"
-	"encoding/gob"
-	"io/ioutil"
-	"log"
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
@@ -178,8 +174,8 @@ func TestRemove(t *testing.T) {
 	var result string
 
 	for _, selval := range []uint{4, 3} {
-		last, _ := l.Index(selval)
-		if v, isfound := l.Remove(selval); isfound {
+		last, _ := l.Index((int)(selval))
+		if v, isfound := l.Remove((int)(selval)); isfound {
 			if v != last {
 				t.Error(v, " != ", last)
 			}
@@ -244,24 +240,56 @@ func TestTraversal(t *testing.T) {
 	}
 }
 
-func loadTestData() []int {
-	data, err := ioutil.ReadFile("../../l.log")
-	if err != nil {
-		log.Println(err)
+func TestRemain(t *testing.T) {
+	l := New()
+	for i := 0; i < 10; i++ {
+		l.Push(i)
+		if !l.Contains(i) {
+			t.Error("Contains", i)
+		}
 	}
-	var l []int
-	decoder := gob.NewDecoder(bytes.NewReader(data))
-	decoder.Decode(&l)
-	return l
-}
 
-func BenchmarkPush(b *testing.B) {
-	l := loadTestData()
-	b.N = len(l)
+	if l.String() != "[0 1 2 3 4 5 6 7 8 9]" {
+		t.Error(l.String())
+	}
 
-	arr := New()
+	for i := 10; i < 100; i++ {
+		l.Push(i)
+	}
 
-	for i := 0; i < b.N; i++ {
-		arr.PushBack(l[i])
+	for !l.Empty() {
+		l.PopBack()
+	}
+
+	for i := 10; i < 100; i++ {
+		l.Push(i)
+	}
+
+	l.Clear()
+
+	if l.Size() != 0 {
+		t.Error("Size != 0")
 	}
 }
+
+// func loadTestData() []int {
+// 	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 BenchmarkPush(b *testing.B) {
+// 	l := loadTestData()
+// 	b.N = len(l)
+
+// 	arr := New()
+
+// 	for i := 0; i < b.N; i++ {
+// 		arr.PushBack(l[i])
+// 	}
+// }
diff --git a/list/array_list/iterator.go b/list/array_list/iterator.go
index fc3acdd..c47f2e9 100644
--- a/list/array_list/iterator.go
+++ b/list/array_list/iterator.go
@@ -7,7 +7,7 @@ type Iterator struct {
 }
 
 func (iter *Iterator) Value() interface{} {
-	v, _ := iter.al.Index(iter.cur)
+	v, _ := iter.al.Index((int)(iter.cur))
 	return v
 }
 
@@ -64,7 +64,7 @@ type CircularIterator struct {
 }
 
 func (iter *CircularIterator) Value() interface{} {
-	v, _ := iter.al.Index(iter.cur)
+	v, _ := iter.al.Index((int)(iter.cur))
 	return v
 }
 
diff --git a/list/linked_list/linked_list.go b/list/linked_list/linked_list.go
index 6c1003d..96bb3f0 100644
--- a/list/linked_list/linked_list.go
+++ b/list/linked_list/linked_list.go
@@ -191,28 +191,34 @@ func (l *LinkedList) FindMany(every func(idx uint, value interface{}) int) (resu
 	return result, isfound
 }
 
-func (l *LinkedList) Index(idx uint) (interface{}, bool) {
-	if idx >= l.size {
+func (l *LinkedList) Index(idx int) (interface{}, bool) {
+
+	if idx < 0 {
+		return nil, false
+	}
+	var uidx = (uint)(idx)
+
+	if uidx >= l.size || idx < 0 {
 		return nil, false
 	}
 
-	if idx > l.size/2 {
-		idx = l.size - 1 - idx
+	if uidx > l.size/2 {
+		uidx = l.size - 1 - uidx
 		// 尾部
 		for cur := l.tail.prev; cur != l.head; cur = cur.prev {
-			if idx == 0 {
+			if uidx == 0 {
 				return cur.value, true
 			}
-			idx--
+			uidx--
 		}
 
 	} else {
 		// 头部
 		for cur := l.head.next; cur != l.tail; cur = cur.next {
-			if idx == 0 {
+			if uidx == 0 {
 				return cur.value, true
 			}
-			idx--
+			uidx--
 		}
 	}
 
@@ -371,33 +377,39 @@ func remove(cur *Node) {
 	cur.next = nil
 }
 
-func (l *LinkedList) Remove(idx uint) (interface{}, bool) {
-	if l.size <= idx {
+func (l *LinkedList) Remove(idx int) (interface{}, bool) {
+
+	if idx < 0 {
+		return nil, false
+	}
+
+	var uidx uint = (uint)(idx)
+	if l.size <= uidx {
 		// log.Printf("out of list range, size is %d, idx is %d\n", l.size, idx)
 		return nil, false
 	}
 
 	l.size--
-	if idx > l.size/2 {
-		idx = l.size - idx // l.size - 1 - idx,  先减size
+	if uidx > l.size/2 {
+		uidx = l.size - uidx // l.size - 1 - idx,  先减size
 		// 尾部
 		for cur := l.tail.prev; cur != l.head; cur = cur.prev {
-			if idx == 0 {
+			if uidx == 0 {
 				remove(cur)
 				return cur.value, true
 			}
-			idx--
+			uidx--
 		}
 
 	} else {
 		// 头部
 		for cur := l.head.next; cur != l.tail; cur = cur.next {
-			if idx == 0 {
+			if uidx == 0 {
 				remove(cur)
 				return cur.value, true
 
 			}
-			idx--
+			uidx--
 		}
 	}
 
diff --git a/list/list.go b/list/list.go
index b53fe6e..bbc482f 100644
--- a/list/list.go
+++ b/list/list.go
@@ -4,10 +4,11 @@ package list
 type IList interface {
 	Push(value interface{})
 	Contains(values ...interface{}) bool
-	Index(idx uint) (interface{}, bool)
-	Remove(idx uint) (result interface{}, isfound bool)
+	Index(idx int) (interface{}, bool)
+	Remove(idx int) (result interface{}, isfound bool)
 	Values() []interface{}
 	Traversal(every func(interface{}) bool)
+	String() string
 
 	Clear()
 	Empty() bool
diff --git a/list/priority_list/priority_list.go b/list/priority_list/priority_list.go
index 8e0128b..63b784d 100644
--- a/list/priority_list/priority_list.go
+++ b/list/priority_list/priority_list.go
@@ -4,6 +4,7 @@ import (
 	"strings"
 
 	"github.com/474420502/focus/compare"
+	"github.com/474420502/focus/list"
 	"github.com/davecgh/go-spew/spew"
 )
 
@@ -20,7 +21,7 @@ type PriorityList struct {
 
 // 优先队列的Index 正负都有作用要定义一种新的接口类型
 func assertImplementation() {
-	// var _ list.IList = (*PriorityList)(nil)
+	var _ list.IList = (*PriorityList)(nil)
 }
 
 func New(Compare compare.Compare) *PriorityList {
@@ -173,11 +174,19 @@ func (pl *PriorityList) GetNode(idx int) (*Node, bool) {
 
 func (pl *PriorityList) RemoveWithIndex(idx int) {
 	if n, ok := pl.GetNode(idx); ok {
-		pl.Remove(n)
+		pl.RemoveNode(n)
 	}
 }
 
-func (pl *PriorityList) Remove(node *Node) {
+func (pl *PriorityList) Remove(idx int) (result interface{}, isfound bool) {
+	if n, ok := pl.GetNode(idx); ok {
+		pl.RemoveNode(n)
+		return n.value, true
+	}
+	return nil, false
+}
+
+func (pl *PriorityList) RemoveNode(node *Node) {
 
 	prev := node.prev
 	next := node.next
diff --git a/map/linked_hashmap/linked_hashmap.go b/map/linked_hashmap/linked_hashmap.go
index fef9fa2..4f9afd9 100644
--- a/map/linked_hashmap/linked_hashmap.go
+++ b/map/linked_hashmap/linked_hashmap.go
@@ -82,7 +82,7 @@ func (lhmap *LinkedHashmap) Remove(key interface{}) (interface{}, bool) {
 func (lhmap *LinkedHashmap) RemoveIndex(idx uint) (interface{}, bool) {
 	if lhmap.list.Size() >= idx {
 		// log.Printf("warn: out of list range, size is %d, idx is %d\n", lhmap.list.Size(), idx)
-		if key, ok := lhmap.list.Remove(idx); ok {
+		if key, ok := lhmap.list.Remove((int)(idx)); ok {
 			result := lhmap.hmap[key]
 			delete(lhmap.hmap, key)
 			return result, true