Merge pull request #313 from jsrdxzw/master

add typescript supported

Author: wangzheng0822

typescript/06_linkedlist/LRUCache.ts

@@ -0,0 +1,106 @@
+/**
+ * 基于Map和双向链表实现的LRU算法
+ * 使用泛型可以存储多种类型的数据
+ */
+class LRUCache<K, V> {
+  private cacheMap: Map<K, LinkedListNode<K, V>>
+  private readonly limit: number
+  private head: LinkedListNode<K, V> | null = null
+  private end: LinkedListNode<K, V> | null = null
+
+  constructor(limit: number) {
+    if (limit <= 0) throw new Error('limit of cache must > 0')
+    this.cacheMap = new Map()
+    this.limit = limit
+  }
+
+  public get(key: K): V | null {
+    const node = this.cacheMap.get(key)
+    if (!node) return null
+    this.refreshNode(node)
+    return node.value
+  }
+
+  public put(key: K, value: V) {
+    const node = this.cacheMap.get(key)
+    // 原缓存不存在则加入到队尾
+    if (!node) {
+      // 大于规定的size则删除最不常用的
+      if (this.cacheMap.size >= this.limit) {
+        const oldKey = this.removeNode(this.head!)
+        this.cacheMap.delete(oldKey)
+      }
+      // 在队尾添加
+      const newNode = new LinkedListNode(key, value)
+      this.addNode(newNode)
+      this.cacheMap.set(key, newNode)
+    } else {
+      node.value = value
+      this.refreshNode(node)
+    }
+  }
+
+  private refreshNode(node: LinkedListNode<K, V>) {
+    if (node === this.end) return
+    this.removeNode(node)
+    this.addNode(node)
+  }
+
+  private removeNode(node: LinkedListNode<K, V>): K {
+    if (node === this.end) {
+      this.end = this.end.prev
+    } else if (node === this.head) {
+      this.head = this.head.next
+    } else {
+      // 这个由于排除了首尾节点
+      node.prev!.next = node.next
+      node.next!.prev = node.prev
+    }
+    return node.key
+  }
+
+  /**
+   * 这里向尾部追加节点
+   * @param node
+   */
+  private addNode(node: LinkedListNode<K, V>) {
+    if (this.end) {
+      this.end.next = node
+      node.prev = this.end
+    }
+    this.end = node
+    if (this.head === null) {
+      this.head = node
+    }
+    // 消除之前的节点的下一个引用对象,防止无限循环
+    node.next = null
+  }
+}
+
+class LinkedListNode<K, V> {
+  key: K
+  value: V
+  next: LinkedListNode<K, V> | null
+  prev: LinkedListNode<K, V> | null
+
+  constructor(
+    key: K,
+    value: V,
+    next: LinkedListNode<K, V> | null = null,
+    prev: LinkedListNode<K, V> | null = null
+  ) {
+    this.key = key
+    this.value = value
+    this.next = next
+    this.prev = prev
+  }
+}
+
+const cache = new LRUCache<string,string>(3)
+cache.put('lv','xzw')
+cache.put('lv2','xzw2')
+cache.put('lv3','xzw3')
+cache.put('lv4','xzw4')
+cache.put('lv5','xzw5')
+
+console.log(cache)

typescript/06_linkedlist/LinkedList.ts

@@ -0,0 +1,132 @@
+/**
+ * 双向链表，更加常用设计也更加复杂一些
+ * 需要更多的存储空间和操作复杂度
+ */
+import List from './List'
+
+class LinkedList<T> implements List<T> {
+  size: number = 0
+  private head: LinkedListNode<T> | null = null
+  private last: LinkedListNode<T> | null = null
+
+  findByIndex(index: number): LinkedListNode<T> | null {
+    let p = this.head
+    let pos = 0
+    while (p && pos !== index) {
+      p = p.next
+      pos++
+    }
+    return p
+  }
+
+  findByValue(value: T): LinkedListNode<T> | null {
+    let p = this.head
+    while (p && p.item !== value) {
+      p = p.next
+    }
+    return p
+  }
+
+  insertToHead(value: T): void {
+    let p = this.head
+    const newNode = new LinkedListNode(value)
+    // 没有元素的时候需要初始化头节点和尾节点
+    if (!p) {
+      this.last = this.head = newNode
+    } else {
+      p.prev = newNode
+      newNode.next = p
+      this.head = newNode
+    }
+    this.size++
+  }
+
+  /**
+   * 在指定的index后面插入节点
+   * @param value 节点的值
+   * @param index 指定的位置
+   */
+  insertToIndex(value: T, index: number): void {
+    let p = this.head
+    let pos = 0
+    const newNode = new LinkedListNode(value)
+    while (p !== null && pos !== index) {
+      p = p.next
+      pos++
+    }
+    if (p === null) return
+    newNode.next = p.next
+    p.next = newNode
+    newNode.prev = p
+    this.size++
+  }
+
+  insertToTail(value: T): void {
+    let p = this.last
+    const newNode = new LinkedListNode(value)
+    if (p === null) {
+      this.head = this.last = newNode
+    } else {
+      p.next = newNode
+      newNode.prev = p
+      this.last = newNode
+    }
+
+    this.size++
+  }
+
+  remove(value: T): boolean {
+    let p = this.head
+    while (p && p.item !== value) {
+      p = p.next
+    }
+    if (!p) return false
+    if (p.prev) {
+      p.prev.next = p.next
+    } else {
+      this.head = p.next
+    }
+    if (p.next) {
+      p.next.prev = p.prev
+    } else {
+      this.last = p.prev
+    }
+    this.size--
+    return true
+  }
+
+  toString(): string {
+    let ret: string = ''
+    let p = this.head
+    while (p) {
+      ret = `${ret} ${p.item} `
+      p = p.next
+    }
+    return ret
+  }
+}
+
+class LinkedListNode<T> {
+  item: T
+  next: LinkedListNode<T> | null
+  prev: LinkedListNode<T> | null
+
+  constructor(
+    item: T,
+    next: LinkedListNode<T> | null = null,
+    prev: LinkedListNode<T> | null = null
+  ) {
+    this.item = item
+    this.next = next
+    this.prev = prev
+  }
+}
+
+const linkedList = new LinkedList()
+linkedList.insertToHead('12')
+linkedList.insertToHead('haha')
+linkedList.insertToHead('www')
+linkedList.insertToTail('zxc')
+linkedList.insertToIndex('12ooo', 0)
+linkedList.remove('12oooo')
+console.log(linkedList.toString())

typescript/06_linkedlist/List.ts

@@ -0,0 +1,19 @@
+interface List<T> {
+  insertToHead(value: T): void
+
+  findByValue(value: T): any
+
+  findByIndex(index: number): any
+
+  insertToIndex(value: T, index: number): void
+
+  remove(value: T): boolean
+
+  insertToHead(value: T): void
+
+  insertToTail(value: T): void
+
+  toString(): string
+}
+
+export default List

typescript/06_linkedlist/SingleLinkedList.ts

@@ -0,0 +1,121 @@
+/**
+ * 1)单链表的插入、删除、查找操作；
+ * 2)链表支持任意类型数据
+ */
+import List from './List'
+
+class SingleLinkedList<T> implements List<T> {
+  // 哨兵头节点
+  private readonly head: SingleNode<T>
+
+  constructor() {
+    this.head = new SingleNode<any>(null)
+  }
+
+  public findByValue(value: T): SingleNode<T> | null {
+    let p = this.head
+    while (p.next != null) {
+      if (p.next.value === value) return p.next
+      p = p.next
+    }
+    return p.next
+  }
+
+  public findByIndex(index: number): SingleNode<T> | null {
+    let p = this.head
+    let pos = 0
+    while (p.next != null && pos !== index) {
+      p = p.next
+      pos++
+    }
+    return p.next
+  }
+
+  /**
+   * 向指定的位置插入节点
+   * @param value
+   * @param index
+   */
+  public insertToIndex(value: T, index: number): void {
+    const newNode = new SingleNode(value)
+    let p = this.head
+    let pos = 0
+    while (p.next != null && pos !== index) {
+      p = p.next
+      pos++
+    }
+    if (p.next == null) return
+    newNode.next = p.next.next
+    p.next.next = newNode
+  }
+
+  /**
+   * 根据值去删除节点
+   * @param value 1 表示删除成功，0 表示删除失败
+   */
+  public remove(value: T): boolean {
+    let p = this.head
+    while (p.next != null) {
+      if (p.next.value === value) break
+      p = p.next
+    }
+    if (p.next === null) return false
+    p.next = p.next.next
+    return true
+  }
+
+  public insertToHead(value: T): void {
+    const newNode = new SingleNode(value, null)
+    this.insertNodeToHead(newNode)
+  }
+
+  public insertToTail(value: T): void {
+    const newNode = new SingleNode(value, null)
+    this.insertNodeToTail(newNode)
+  }
+
+  private insertNodeToHead(node: SingleNode<T>): void {
+    node.next = this.head.next
+    this.head.next = node
+  }
+
+  public toString(): string {
+    let ret: string = ''
+    let p = this.head
+    while (p.next != null) {
+      ret = `${ret} ${p.next.value} `
+      p = p.next
+    }
+    return ret
+  }
+
+  /**
+   * 单链表的尾插入比较费时
+   * @param newNode 插入的新节点
+   */
+  private insertNodeToTail(newNode: SingleNode<T>): void {
+    let p = this.head
+    while (p.next != null) {
+      p = p.next
+    }
+    p.next = newNode
+  }
+}
+
+class SingleNode<T> {
+  public value: T
+  public next: SingleNode<T> | null
+
+  constructor(value: T, next: SingleNode<T> | null = null) {
+    this.value = value
+    this.next = next
+  }
+}
+
+const singleLinkedList = new SingleLinkedList<string>()
+singleLinkedList.insertToTail('god')
+singleLinkedList.insertToTail('my')
+// console.log(singleLinkedList.printLinkedList())
+singleLinkedList.insertToIndex('haha', 1)
+singleLinkedList.remove('ha1')
+singleLinkedList.toString()