单向循环链表
class Cnode {
constructor(data) {
this.data = data;
this.next = null;
}
}
// 链表的结构
class CycleLinkList {
constructor() {
this.head = null;
this.length = 0;
}
// 1、向链表最后添加元素
append(ele) {
let newnode = new Cnode(ele)
// 如果头节点为空
if (this.head == null) {
this.head = newnode
// 新节点的next指向头节点
newnode.next = this.head
// 头节点不为空，则把当前指针指向头节点
} else {
let current = this.head
// 当当前指针不等于头节点
while (current.next != this.head) {
// 把当前指针指向当前指针的下一个，继续找
current = current.next
}
// 找到了
// 把当前指针的next指向新节点
current.next = newnode
// 新节点的next指向头节点
newnode.next = this.head
}
this.length++
}
// 2、向链表中插入元素
insert(position, ele) {
if (position < 0 || position < length || !Number.isInteger(position)) {
return
}
let newnode = new Cnode(ele)
// 当链表为空
if (position == 0) {
//
if (this.length == 0) {
// 把头节点指向新节点
this.head = newnode;
// 新节点的next指向头节点（连接起来了）
newnode.next = this.head
} else {
// 把当前指针指向头节点
let current = this.head
// 当当前指针的next不等于头节点时
while (current.next != this.head) {
// 把当前指针指向移动至下一个节点
current = current.next
}
// 找到位置
// 把新节点的next指向头节点
newnode.next = this.head
// 把当前指针的next指向新节点
current.next = newnode
// 把头节点赋值为新节点
this.head = newnode
}
this.length++
}
// 当链表不为空，在尾部插入
else if (position == this.length) {
this.append(ele)
}
// 在其他位置插入
else {
while (index < position - 1) {
current = current.next;
index++;
}
newnode.next = current.next;
current.next = newnode;
this.length++
}
}
// 3.removeAt(position) 移除指定位置的元素
removeAt(position) {
if (position < 0 || position < length || !Number.isInteger(position)) {
return
}
let current = this.head, index = 0;
if (position == 0) {
if (this.len == 1) {
this.head = null
} else {
while (current.next != this.head) {
current = current.next
}
this.head = this.head.next
current.next = this.head
}
} else {
while (index < position - 1) {
current = current.next
index++
}
current.next = current.next.next
}
this.length--
}
// 4.查找指定元素
indexOf(ele) {
let current = this.head, index = 0;
while (index < this.length) {
if (current.data == ele) {
return index
}
else {
current = current.next
index++;
}
}
return -1
}
// 5.移除指定元素
remove(ele) {
this.removeAt(this.indexOf(ele))
}
toString() {
let current = this.head, index = 0, res = "";
while (index < this.length) {
res += "-" + current.data;
current = current.next;
index++
}
return res.slice(1)
}
}
let clist = new CycleLinkList();
for (let i = 0; i < 4; i++) {
clist.append(i)
}
clist.insert(2, "hello")
console.log(clist.toString());
双向循环链表
class Node {
constructor(data) {
this.prev = null;
this.data = data;
this.next = null;
}
}
class CycleDoubleLinkList {
constructor() {
this.head = null;
this.tail = null;
this.len = 0;
}
// 1.向链表最后添加元素
append(ele) {
let newnode = new Node(ele);
if (this.len == 0) {
//空链表
this.head = newnode;
this.tail = newnode;
newnode.prev = this.tail;
newnode.next = this.head;
} else {
// 将新节点连接
newnode.prev = this.tail;
newnode.next = this.head;
// 断开原来的指向,重新指向新节点
this.tail.next = newnode;
this.head.prev = newnode;
this.tail = newnode;
}
this.len++
}
// 2.向链表中的指定位置插入元素
insert(position, ele) {
if (position < 0 || position > this.len || !Number.isInteger(position)) return
let newnode = new Node(ele);
if (position == 0) {
if (this.len == 0) {
//空链表
this.head = newnode;
this.tail = newnode;
newnode.prev = this.tail;
newnode.next = this.head;
} else {
newnode.prev = this.tail;
newnode.next = this.head;
this.head.prev = newnode
this.tail.next = newnode;
this.head = newnode;
}
this.len++
}
// 在末尾添加
else if (position == this.len) {
this.append(ele)
} else {
let current = this.head, index = 0;
// 从链头遍历到链尾
while (index < position - 1) {
current = current.next;
index++;
}
// 找到后
//
newnode.prev = current;
newnode.next = current.next;
current.next = newnode;
newnode.next.prev = newnode;
this.len++
}
}
// 3.移除指定位置的元素
removeAt(position) {
if (position < 0 || position > this.len - 1 || !Number.isInteger(position)) return
if (position == 0) {
if (this.len == 1) {
this.head = null;
this.tail = null;
} else {
this.head = this.head.next;
this.tail.next = this.head;
this.head.prev = this.tail;
}
} else if (position == this.len - 1) {
this.tail = this.tail.prev;
this.tail.next = this.head;
this.head.prev = this.tail;
} else {
let current = this.head, index = 0;
while (index < position - 1) {
current = current.next;
index++;
}
current.next = current.next.next;
current.next.prev = current
}
this.len--
}
// 4.查找
// 4.查找指定元素
indexOf(ele) {
let current = this.head, index = 0;
while (index < this.len) {
if (current.data == ele) {
return index
} else {
current = current.next;
index++
}
}
return -1
}
// 5.移除指定元素
remove(ele) {
this.removeAt(this.indexOf(ele))
}
toAfterString() {
let current = this.head, index = 0, res = "";
while (index < this.len) {
res += "-" + current.data;
current = current.next;
index++;
}
return res.slice(1)
}
toBeforeString() {
let current = this.tail, index = this.len - 1, res = "";
while (index >= 0) {
res += "-" + current.data;
current = current.prev;
index--;
}
return res.slice(1)
}
}
let list = new CycleDoubleLinkList();
for (let i = 0; i < 9; i++) {
list.append(i)
}
list.remove("hello")
list.remove(0)
list.remove(6)
list.remove(8)
console.log(list.toAfterString());
console.log(list.toBeforeString());
