From 4b5b902e65409b49357e94001f2354ef9360d1f6 Mon Sep 17 00:00:00 2001
From: huangsimin <huangsimin@youmi.net>
Date: Thu, 6 Dec 2018 10:36:11 +0800
Subject: [PATCH] v0.0.1

---
 .gitignore                              |   2 +
 circular_linked/circular_linked.go      | 239 ++++++++++++++++++++++++
 circular_linked/circular_linked_test.go |   1 +
 3 files changed, 242 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 circular_linked/circular_linked.go
 create mode 100644 circular_linked/circular_linked_test.go

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..edd36a0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+main
+*.debug
diff --git a/circular_linked/circular_linked.go b/circular_linked/circular_linked.go
new file mode 100644
index 0000000..714442e
--- /dev/null
+++ b/circular_linked/circular_linked.go
@@ -0,0 +1,239 @@
+package circular_linked
+
+import (
+	"log"
+	"strings"
+
+	"github.com/davecgh/go-spew/spew"
+)
+
+// CNode 循环链表 三色标记 不确定是否会清除循环引用, 网上说会
+type CNode struct {
+	value interface{}
+	prev  *CNode
+	next  *CNode
+}
+
+// GetValue 获取到Node的值
+func (node *CNode) GetValue() interface{} {
+	return node.value
+}
+
+// SetValue 获取到Node的值
+func (node *CNode) SetValue(value interface{}) {
+	node.value = value
+}
+
+// CircularLinked 循环链表
+type CircularLinked struct {
+	cursor *CNode
+	head   *CNode
+	tail   *CNode
+	size   uint64
+}
+
+// NewCircularLinked create a CircularLinked
+func NewCircularLinked(values ...interface{}) *CircularLinked {
+	list := &CircularLinked{}
+	if len(values) > 0 {
+		list.Append(values...)
+	}
+	return list
+}
+
+// Cursor get current Cursor
+func (list *CircularLinked) Cursor() *CNode {
+	if list.cursor == nil {
+		list.cursor = list.head
+	}
+	return list.cursor
+}
+
+// MoveNext get next Cursor
+func (list *CircularLinked) MoveNext() *CNode {
+	if list.cursor == nil {
+		list.cursor = list.head
+	}
+	list.cursor = list.cursor.next
+	return list.cursor
+}
+
+// MovePrev get prev Cursor
+func (list *CircularLinked) MovePrev() *CNode {
+	if list.cursor == nil {
+		list.cursor = list.head
+	}
+	list.cursor = list.cursor.prev
+	return list.cursor
+}
+
+// CursorToHead cursor move to head
+func (list *CircularLinked) CursorToHead() *CNode {
+	list.cursor = list.head
+	return list.cursor
+}
+
+// CursorToTail cursor move to tail
+func (list *CircularLinked) CursorToTail() *CNode {
+	list.cursor = list.tail
+	return list.cursor
+}
+
+// GetLoopValues 获取从头到尾的值
+func (list *CircularLinked) GetLoopValues() []*CNode {
+	var result []*CNode
+
+	if list.head != nil {
+		result = append(result, list.head)
+		for cur := list.head.next; cur != list.head; cur = cur.next {
+			result = append(result, cur)
+		}
+	}
+	return result
+}
+
+// Append a value (one or more) at the end of the list (same as Append())
+func (list *CircularLinked) Append(values ...interface{}) {
+	for _, value := range values {
+		node := &CNode{value: value}
+		if list.size == 0 {
+			list.head = node
+			list.tail = node
+			node.next = node
+			node.prev = node
+		} else {
+			list.tail.next = node
+			node.next = list.head
+			node.prev = list.tail
+			list.tail = node
+		}
+		list.size++
+	}
+}
+
+// Remove 移除一些节点
+func (list *CircularLinked) Remove(node *CNode) {
+
+	switch list.size {
+	case 0:
+		list.errorNotInList(node)
+	case 1:
+		if list.head == node {
+			list.head = nil
+			list.tail = nil
+			node.next = nil
+			node.prev = nil
+			list.cursor = nil
+			list.size--
+		} else {
+			list.errorNotInList(node)
+		}
+	case 2:
+
+		node.prev = nil
+		node.next = nil
+
+		switch node {
+		case list.head:
+			list.head = list.tail
+			list.tail.prev = list.head
+			list.head.next = list.tail
+			list.cursor = list.head
+			list.size--
+		case list.tail:
+			list.tail = list.head
+			list.tail.prev = list.head
+			list.head.next = list.tail
+			list.cursor = list.head
+			list.size--
+		default:
+			list.errorNotInList(node)
+		}
+
+	default:
+		switch node {
+		case list.head:
+			_, next := list.cutAndSplice(node)
+			list.size--
+			list.head = next
+			if list.cursor == node {
+				list.cursor = next
+			}
+		case list.tail:
+			prev, _ := list.cutAndSplice(node)
+			list.size--
+			list.tail = prev
+			if list.cursor == node {
+				list.cursor = prev
+			}
+		default:
+			_, next := list.cutAndSplice(node)
+			list.size--
+			if list.cursor == node {
+				list.cursor = next
+			}
+		}
+	}
+
+}
+
+// LookCursor for list show
+func (list *CircularLinked) LookCursor() string {
+	cursor := list.Cursor()
+
+	content := "->["
+	cur := list.head
+	if list.size != 0 {
+		for size := uint64(0); size < list.size; size++ {
+			if cursor == cur {
+				content += "(" + spew.Sprint(cur.value) + ")" + ", "
+			} else {
+				content += spew.Sprint(cur.value) + ", "
+			}
+
+			cur = cur.next
+		}
+	}
+	content = strings.TrimRight(content, ", ")
+	showlen := len(content)
+	if showlen >= 64 {
+		showlen = 64
+	}
+	content += "]" + content[0:showlen] + " ..."
+	return content
+}
+
+// Clear for list show
+func (list *CircularLinked) Clear() {
+	if list.size != 0 {
+		list.head.prev = nil
+		list.tail.next = nil
+		list.head = nil
+		list.tail = nil
+		list.cursor = nil
+		list.size = 0
+	}
+}
+
+// Size for list show
+func (list *CircularLinked) Size() uint64 {
+	return list.size
+}
+
+func (list *CircularLinked) errorNotInList(node *CNode) {
+	log.Println("the node value ", spew.Sprint(node), " is not in list")
+}
+
+// cutAndSplice (不考虑边界情况)
+func (list *CircularLinked) cutAndSplice(node *CNode) (prev, next *CNode) {
+	prev = node.prev
+	next = node.next
+
+	prev.next = next
+	next.prev = prev
+
+	node.prev = nil
+	node.next = nil
+
+	return prev, next
+}
diff --git a/circular_linked/circular_linked_test.go b/circular_linked/circular_linked_test.go
new file mode 100644
index 0000000..980014b
--- /dev/null
+++ b/circular_linked/circular_linked_test.go
@@ -0,0 +1 @@
+package circular_linked