Kotlin ListNode链表

ListNode.kt

package com

/*
 * @Author: Hasiy
 * @Date: 2020/4/1 - 16 : 47 
 * @Description: institute-Android
 * @Email: Zhuxs@venpoo.com
 */
class ListNode<T>(val value: T) {
    var next: ListNode<T>? = null
    override fun toString(): String {
        return "$value -> ${next?.value ?: "null"}"
    }
}

fun <T> ListNode<T>?.toList(): List<T> {
    this?.let {
        val list = ArrayList<T>()
        var tempNode: ListNode<T>? = this
        while (tempNode != null) {
            list += tempNode.value
            tempNode = tempNode.next
        }
        return list
    } ?: return emptyList()
}

//单向链表
class LinkedNode<T>(var value: T) {
    var next: LinkedNode<T>? = null //指向下一个存储节点的next指针
}

//双向链表
class DoubleLinkedNode<T>(var value: T) {
    var prev: DoubleLinkedNode<T>? = null //指向上一个存储节点的prev指针
    var next: DoubleLinkedNode<T>? = null //指向下一个存储节点的next指针
}

//栈
class LinkedStack {
    private var first: Node? = null
    private var len: Int = 0

    fun push(value: Int) {//相当于链表从表头插入新的元素
        val oldFirst = first
        first = Node(value)
        first?.next = oldFirst
        len++
    }

    fun pop(): Int {//相当于链表从表头删除新的元素
        val value = first?.value
        first = first?.next
        return value ?: -1
    }

    fun top(): Int {
        return first?.value ?: -1
    }

    fun isEmpty(): Boolean {
        return first == null
    }

    fun size(): Int {
        return len
    }

    inner class Node(var value: Int) {
        var next: Node? = null
    }
}

//队列
class LinkedQueue {
    private var first: Node? = null
    private var last: Node? = null
    private var len: Int = 0

    fun enqueue(value: Int) {//相当于链表从尾部插入新的节点
        val oldLast = last
        last = Node(value)
        last?.next = null
        if (isEmpty()) {
            first = last
        } else {
            oldLast?.next = last
        }
        len++
    }

    fun dequeue(): Int {//相当于链表从尾部删除最后节点
        val value = first?.value ?: -1
        first = first?.next
        if (isEmpty()) {
            last = null
        }
        return value
    }

    fun isEmpty(): Boolean {
        return first == null
    }

    fun size(): Int {
        return len
    }

    inner class Node(var value: Int) {
        var next: Node? = null
    }
}