fix linkedlist

list/linkedlist/linkedlist.go

@@ -121,6 +121,34 @@ func (l *LinkedList) Back() (result interface{}, found bool) {
 	return nil, false
 }
 
+func (l *LinkedList) Index(idx uint) (interface{}, bool) {
+	if idx >= l.size {
+		return nil, false
+	}
+
+	if idx > l.size/2 {
+		idx = l.size - 1 - idx
+		// 尾部
+		for cur := l.tail.prev; cur != nil; cur = cur.prev {
+			if idx == 0 {
+				return cur.value, true
+			}
+			idx--
+		}
+
+	} else {
+		// 头部
+		for cur := l.head.next; cur != nil; cur = cur.next {
+			if idx == 0 {
+				return cur.value, true
+			}
+			idx--
+		}
+	}
+
+	return nil, false
+}
+
 func (l *LinkedList) Insert(idx uint, values ...interface{}) {
 	if idx > l.size {
 		return
@@ -196,33 +224,81 @@ func (l *LinkedList) Insert(idx uint, values ...interface{}) {
 	l.size += uint(len(values))
 }
 
-func (l *LinkedList) Remove(idx uint) {
+func (l *LinkedList) InsertIf(every func(idx uint, cur *Node) int, values ...interface{}) {
+
+	idx := uint(0)
+	// 头部
+	for cur := l.head.next; cur != nil; cur = cur.next {
+
+		if every(idx, cur) != 0 { // 1 为前 -1 为后
+
+			var start *Node
+			var end *Node
+
+			start = &Node{value: values[0]}
+			end = start
+
+			for _, value := range values[1:] {
+				node := &Node{value: value}
+				end.next = node
+				node.prev = end
+				end = node
+			}
+
+			cprev := cur.prev
+
+			cprev.next = start
+			start.prev = cprev
+
+			end.next = cur
+			cur.prev = end
+
+		}
+
+	}
+
+	l.size += uint(len(values))
+}
+
+func (l *LinkedList) Remove(idx uint) (interface{}, bool) {
 	if idx >= l.size {
 		panic(fmt.Sprintf("out of list range, size is %d, idx is %d", l.size, idx))
 	}
-	if l.head != nil {
+
-		if idx == 0 {
+	if idx > l.size/2 {
-			l.size--
+		idx = l.size - 1 - idx
-			temp := l.head
+		// 尾部
-			l.head = l.head.next
+		for cur := l.tail.prev; cur != nil; cur = cur.prev {
-			nodePool.Put(temp)
+			if idx == 0 {
-			return
+				curPrev := cur.prev
+				curNext := cur.next
+				curPrev.next = curNext
+				curNext.prev = curPrev
+				cur.prev = nil
+				cur.next = nil
+				return cur.value, true
+			}
+			idx--
 		}
 
-		for cur := l.head; cur.next != nil; cur = cur.next {
+	} else {
-			if idx == 1 {
+		// 头部
-				l.size--
+		for cur := l.head.next; cur != nil; cur = cur.next {
-				result := cur.next
+			if idx == 0 {
-				cur.next = result.next
+				curPrev := cur.prev
-				result.next = nil
+				curNext := cur.next
-				nodePool.Put(result)
+				curPrev.next = curNext
-				return
+				curNext.prev = curPrev
+				cur.prev = nil
+				cur.next = nil
+				return cur.value, true
+
 			}
 			idx--
 		}
 	}
 
-	return
+	panic(fmt.Sprintf("unknown error"))
 }
 
 func (l *LinkedList) Values() (result []interface{}) {

list/linkedlist/linkedlist_test.go

@@ -45,7 +45,7 @@ func TestPushBack(t *testing.T) {
 
 func TestPopFront(t *testing.T) {
 	l := New()
-	// "[0 1 2 3 4]"
+	// "[4 3 2 1 0]"
 	for i := 0; i < 5; i++ {
 		l.PushFront(i)
 	}
@@ -68,7 +68,7 @@ func TestPopFront(t *testing.T) {
 
 func TestPopBack(t *testing.T) {
 	l := New()
-	// "[0 1 2 3 4]"
+	// "[4 3 2 1 0]"
 	for i := 0; i < 5; i++ {
 		l.PushFront(i)
 	}
@@ -127,6 +127,58 @@ func TestInsert(t *testing.T) {
 	if result1 != "[4 99 3 2 1 0 0 1 2 3 4]" {
 		t.Error("[4 3 2 1 0 0 1 2 3 4] insert with index 1, should be [4 99 3 2 1 0 0 1 2 3 4]\n but result is", result1)
 	}
+
+	l1.Insert(9, 99)
+	result1 = spew.Sprint(l1.Values())
+	if result1 != "[4 99 3 2 1 0 0 1 2 99 3 4]" {
+		t.Error("[4 99 3 2 1 0 0 1 2 3 4] insert with index 9, should be [4 99 3 2 1 0 0 1 2 99 3 4]\n but result is", result1)
+	}
+
+	l1.Insert(12, 99)
+	result1 = spew.Sprint(l1.Values())
+	if result1 != "[4 99 3 2 1 0 0 1 2 99 3 4 99]" {
+		t.Error("[4 99 3 2 1 0 0 1 2 99 3 4] insert with index 12, should be [4 99 3 2 1 0 0 1 2 99 3 4 99]\n but result is", result1)
+	}
+}
+
+func TestIndex(t *testing.T) {
+	l := New()
+	// "[4 3 2 1 0]"
+	for i := 0; i < 5; i++ {
+		l.PushFront(i)
+	}
+
+	if v, ok := l.Index(4); ok {
+		if v != 0 {
+			t.Error("[4 3 2 1 0] Index 4 value is 0, but v is ", v)
+		}
+	} else {
+		t.Error("not ok is error")
+	}
+
+	if v, ok := l.Index(1); ok {
+		if v != 3 {
+			t.Error("[4 3 2 1 0] Index 1 value is 3, but v is ", v)
+		}
+	} else {
+		t.Error("not ok is error")
+	}
+
+	if v, ok := l.Index(0); ok {
+		if v != 4 {
+			t.Error("[4 3 2 1 0] Index 1 value is 4, but v is ", v)
+		}
+	} else {
+		t.Error("not ok is error")
+	}
+
+	if _, ok := l.Index(5); ok {
+		t.Error("[4 3 2 1 0] Index 5, out of range,ok = true is error")
+	}
+}
+
+func TestRemove(t *testing.T) {
+
 }
 
 func BenchmarkPushBack(b *testing.B) {