痛苦就是在蜕变吗
目录
链表：
链表就是一种物理存储单元上非连续、非顺序的存储结构，数据元素的逻辑顺序是通过链表中的指针连接次序实现的。链表由一系列结点组成，结点可以在运行时动态的生成。
每个结点包括两个部分：一个是存储数据元素的数据域，另一个是存储下一个结点地址的指针域。
链表的特点：
- 插入、删除数据效率 O(1)级别（只需要更改指针指向即可），随机访问效率低 O(n)级别 （需要从链头至链尾进行遍历）
- 和数组相比，内存空间消耗更大，因为每个存储数据的节点都需要额外的空间存储后继指针。
单链表：
每个节点只包含一个指针，即后继指针。
单链表的封装- JS封装：
javascript
<script>
class Node {
constructor(element) {
this.element = element;
this.next = null;
}
}
class LinkedList {
// #
constructor() {
this.count = 0;
this.head = null;
}
// push 添加一个节点
push (element) {
const node = new Node(element);
// header是空
if (this.head === null) {
this.head = node;
} else {
let current = this.head;
while (current.next !== null) {
current = current.next;
}
current.next = node;
}
this.count++;
}
// 指定位置删除 传入索引
removeAt (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous;
for (let i = 0; i < index; i++) {
previous = current;
current = current.next;
}
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 指定位置删除-方法二利用getNodeAt(index) 传入索引
removeAt2 (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous = this.getNodeAt(index - 1);
current = previous.next;
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 根据索引获得节点node
getNodeAt (index) {
if (index >= 0 && index < this.count) {
let node = this.head;
for (let i = 0; i < index; i++) {
node = node.next;
}
return node;
}
return;
}
// 判断是否相等
equalFn (a, b) {
// 暴力写法:
// 也有缺陷 JSON.stringify({a:1,b:2}) !== JSON.stringify({b:2,a:1})
return JSON.stringify(a) === JSON.stringify(b);
// 可以使用第三方库
}
// 根据元素返回索引
indexOf (element) {
let current = this.head;
for (let i = 0; i < this.count; i++) {
if (this.equalFn(current.element, element)) {
return i;
}
current = current.next;
}
}
// 直接根据值删除
remove (element) {
// 根据数据返回索引的方法
const index = this.indexOf(element);
return this.removeAt(index);
}
// 指定位置插入内容
insert (element, index) {
if (index >= 0 && index <= this.count) {
const node = new Node(element);
if (index == 0) {
const current = this.head;
node.next = current;
this.head = node;
} else {
const previous = this.getNodeAt(index - 1);
const current = previous.next;
previous.next = node;
node.next = current;
}
this.count++;
return true;
}
return false;
}
// 判断是否为空
isEmpty () {
return this.size() === 0;
}
// 判断长度
size () {
return this.count;
}
// 返回链头
getHead () {
return this.head;
}
}
let list = new LinkedList()
</script>单链表的应用：
解决回文：
举个例子，当初判断回文的时候我们使用的双端队列，在这里使用单链表解决:
javascript
<script>
class Node {
constructor(element) {
this.element = element;
this.next = null;
}
}
class LinkedList {
// #
constructor() {
this.count = 0;
this.head = null;
}
// push 添加一个节点
push (element) {
const node = new Node(element);
// header是空
if (this.head === null) {
this.head = node;
} else {
let current = this.head;
while (current.next !== null) {
current = current.next;
}
current.next = node;
}
this.count++;
}
// 指定位置删除 传入索引
removeAt (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous;
for (let i = 0; i < index; i++) {
previous = current;
current = current.next;
}
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 指定位置删除-方法二利用getNodeAt(index) 传入索引
removeAt2 (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous = this.getNodeAt(index - 1);
current = previous.next;
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 根据索引获得节点node
getNodeAt (index) {
if (index >= 0 && index < this.count) {
let node = this.head;
for (let i = 0; i < index; i++) {
node = node.next;
}
return node;
}
return;
}
// 判断是否相等
equalFn (a, b) {
// 暴力写法:
// 也有缺陷 JSON.stringify({a:1,b:2}) !== JSON.stringify({b:2,a:1})
return JSON.stringify(a) === JSON.stringify(b);
// 可以使用第三方库
}
// 根据元素返回索引
indexOf (element) {
let current = this.head;
for (let i = 0; i < this.count; i++) {
if (this.equalFn(current.element, element)) {
return i;
}
current = current.next;
}
}
// 直接根据值删除
remove (element) {
// 根据数据返回索引的方法
const index = this.indexOf(element);
return this.removeAt(index);
}
// 指定位置插入内容
insert (element, index) {
if (index >= 0 && index <= this.count) {
const node = new Node(element);
if (index == 0) {
const current = this.head;
node.next = current;
this.head = node;
} else {
const previous = this.getNodeAt(index - 1);
const current = previous.next;
previous.next = node;
node.next = current;
}
this.count++;
return true;
}
return false;
}
// 判断是否为空
isEmpty () {
return this.size() === 0;
}
// 判断长度
size () {
return this.count;
}
// 返回链头
getHead () {
return this.head;
}
}
</script>
<script>
// 使用单链表解决回文问题
function test (str) {
const lowstr = str.toLocaleLowerCase().split(" ").join("");
let list = new LinkedList();
for (let i = 0; i < lowstr.length; i++) {
list.push(lowstr[i]);
}
let isEqual = true;
while (list.size() > 1) {
if (list.removeAt(0) !== list.removeAt(list.size() - 1)) {
isEqual = false;
break;
}
}
return isEqual;
}
test("D a d");
</script>解决击鼓传花：
举个例子，当初击鼓传花的时候我们使用的队列，在这里使用单链表解决:
javascript
<script>
class Node {
constructor(element) {
this.element = element;
this.next = null;
}
}
class LinkedList {
// #
constructor() {
this.count = 0;
this.head = null;
}
// push 添加一个节点
push (element) {
const node = new Node(element);
// header是空
if (this.head === null) {
this.head = node;
} else {
let current = this.head;
while (current.next !== null) {
current = current.next;
}
current.next = node;
}
this.count++;
}
// 指定位置删除 传入索引
removeAt (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous;
for (let i = 0; i < index; i++) {
previous = current;
current = current.next;
}
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 指定位置删除-方法二利用getNodeAt(index) 传入索引
removeAt2 (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous = this.getNodeAt(index - 1);
current = previous.next;
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 根据索引获得节点node
getNodeAt (index) {
if (index >= 0 && index < this.count) {
let node = this.head;
for (let i = 0; i < index; i++) {
node = node.next;
}
return node;
}
return;
}
// 判断是否相等
equalFn (a, b) {
// 暴力写法:
// 也有缺陷 JSON.stringify({a:1,b:2}) !== JSON.stringify({b:2,a:1})
return JSON.stringify(a) === JSON.stringify(b);
// 可以使用第三方库
}
// 根据元素返回索引
indexOf (element) {
let current = this.head;
for (let i = 0; i < this.count; i++) {
if (this.equalFn(current.element, element)) {
return i;
}
current = current.next;
}
}
// 直接根据值删除
remove (element) {
// 根据数据返回索引的方法
const index = this.indexOf(element);
return this.removeAt(index);
}
// 指定位置插入内容
insert (element, index) {
if (index >= 0 && index <= this.count) {
const node = new Node(element);
if (index == 0) {
const current = this.head;
node.next = current;
this.head = node;
} else {
const previous = this.getNodeAt(index - 1);
const current = previous.next;
previous.next = node;
node.next = current;
}
this.count++;
return true;
}
return false;
}
// 判断是否为空
isEmpty () {
return this.size() === 0;
}
// 判断长度
size () {
return this.count;
}
// 返回链头
getHead () {
return this.head;
}
}
</script>
<script>
// 击鼓传花
function game (list, num) {
let List = new LinkedList();
for (let i = 0; i < list.length; i++) {
List.push(list[i]);
}
while (List.size() > 1) {
for (let i = 0; i < num; i++) {
List.push(List.removeAt(0));
}
console.log(List.removeAt(0), '淘汰了');
}
console.log('获胜的是：', List.removeAt(0));
}
game(['kitty', 'Alice', 'AK', 'Box', 'Whe'], 7);
</script>
十进制进制转换其他进制：
举个例子，当初十进制转换其他进制的时候我们使用的栈，在这里使用单链表解决:
javascript
<script>
class Node {
constructor(element) {
this.element = element;
this.next = null;
}
}
class LinkedList {
// #
constructor() {
this.count = 0;
this.head = null;
}
// push 添加一个节点
push (element) {
const node = new Node(element);
// header是空
if (this.head === null) {
this.head = node;
} else {
let current = this.head;
while (current.next !== null) {
current = current.next;
}
current.next = node;
}
this.count++;
}
// 指定位置删除 传入索引
removeAt (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous;
for (let i = 0; i < index; i++) {
previous = current;
current = current.next;
}
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 指定位置删除-方法二利用getNodeAt(index) 传入索引
removeAt2 (index) {
if (index >= 0 && index < this.count) {
let current = this.head;
if (index == 0) {
this.head = this.head.next;
} else {
let previous = this.getNodeAt(index - 1);
current = previous.next;
previous.next = current.next;
}
this.count--;
return current.element;
}
return;
}
// 根据索引获得节点node
getNodeAt (index) {
if (index >= 0 && index < this.count) {
let node = this.head;
for (let i = 0; i < index; i++) {
node = node.next;
}
return node;
}
return;
}
// 判断是否相等
equalFn (a, b) {
// 暴力写法:
// 也有缺陷 JSON.stringify({a:1,b:2}) !== JSON.stringify({b:2,a:1})
return JSON.stringify(a) === JSON.stringify(b);
// 可以使用第三方库
}
// 根据元素返回索引
indexOf (element) {
let current = this.head;
for (let i = 0; i < this.count; i++) {
if (this.equalFn(current.element, element)) {
return i;
}
current = current.next;
}
}
// 直接根据值删除
remove (element) {
// 根据数据返回索引的方法
const index = this.indexOf(element);
return this.removeAt(index);
}
// 指定位置插入内容
insert (element, index) {
if (index >= 0 && index <= this.count) {
const node = new Node(element);
if (index == 0) {
const current = this.head;
node.next = current;
this.head = node;
} else {
const previous = this.getNodeAt(index - 1);
const current = previous.next;
previous.next = node;
node.next = current;
}
this.count++;
return true;
}
return false;
}
// 判断是否为空
isEmpty () {
return this.size() === 0;
}
// 判断长度
size () {
return this.count;
}
// 返回链头
getHead () {
return this.head;
}
}
</script>
<script>
// 十进制进制转换其他进制
function convert (decNumber, base) {
let list = new LinkedList();
let string = "";
let number = decNumber;
let baseString = "0123456789ABCDEF"
while (number > 0) {
list.push(number % base);
number = Math.floor(number / base);
}
while (!(list.isEmpty())) {
string += baseString[list.removeAt(list.size() - 1)];
}
return string;
}
convert(50, 8)
</script>