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Add kotlin code for the chapter of stack and queue (#1162)
* modified array.kt. * feat(kotlin): add kotlin code for the chapter of stack and queue. * modified array.kt * modified comments.
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144
codes/kotlin/chapter_stack_and_queue/array_deque.kt
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144
codes/kotlin/chapter_stack_and_queue/array_deque.kt
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/**
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* File: array_deque.kt
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* Created Time: 2024-01-25
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* Author: curtishd (1023632660@qq.com)
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*/
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package chapter_stack_and_queue
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/* 基于环形数组实现的双向队列 */
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class ArrayDeque(capacity: Int) {
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private var nums = IntArray(capacity) // 用于存储双向队列元素的数组
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private var front = 0 // 队首指针,指向队首元素
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private var queSize = 0 // 双向队列长度
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/* 获取双向队列的容量 */
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fun capacity(): Int {
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return nums.size
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}
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/* 获取双向队列的长度 */
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fun size(): Int {
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return queSize
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}
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/* 判断双向队列是否为空 */
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fun isEmpty(): Boolean {
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return queSize == 0
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}
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/* 计算环形数组索引 */
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private fun index(i: Int): Int {
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// 通过取余操作实现数组首尾相连
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// 当 i 越过数组尾部后,回到头部
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// 当 i 越过数组头部后,回到尾部
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return (i + capacity()) % capacity()
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}
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/* 队首入队 */
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fun pushFirst(num: Int) {
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if (queSize == capacity()) {
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println("双向队列已满")
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return
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}
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// 队首指针向左移动一位
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// 通过取余操作实现 front 越过数组头部后回到尾部
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front = index(front - 1)
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// 将 num 添加至队首
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nums[front] = num
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queSize++
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}
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/* 队尾入队 */
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fun pushLast(num: Int) {
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if (queSize == capacity()) {
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println("双向队列已满")
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return
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}
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// 计算队尾指针,指向队尾索引 + 1
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val rear = index(front + queSize)
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// 将 num 添加至队尾
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nums[rear] = num
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queSize++
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}
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/* 队首出队 */
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fun popFirst(): Int {
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val num = peekFirst()
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// 队首指针向后移动一位
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front = index(front + 1)
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queSize--
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return num
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}
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/* 访问队尾元素 */
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fun popLast(): Int {
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val num = peekLast()
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queSize--
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return num
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}
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/* 访问队首元素 */
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fun peekFirst(): Int {
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if (isEmpty()) throw IndexOutOfBoundsException()
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return nums[front]
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}
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/* 访问队尾元素 */
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fun peekLast(): Int {
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if (isEmpty()) throw IndexOutOfBoundsException()
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// 计算尾元素索引
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val last = index(front + queSize - 1)
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return nums[last]
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}
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/* 返回数组用于打印 */
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fun toArray(): IntArray {
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// 仅转换有效长度范围内的列表元素
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val res = IntArray(queSize)
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var i = 0
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var j = front
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while (i < queSize) {
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res[i] = nums[index(j)]
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i++
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j++
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}
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return res
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}
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}
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/* Driver Code */
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fun main() {
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/* 初始化双向队列 */
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val deque = ArrayDeque(10)
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deque.pushLast(3)
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deque.pushLast(2)
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deque.pushLast(5)
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println("双向队列 deque = ${deque.toArray().contentToString()}")
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/* 访问元素 */
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val peekFirst = deque.peekFirst()
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println("队首元素 peekFirst = $peekFirst")
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val peekLast = deque.peekLast()
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println("队尾元素 peekLast = $peekLast")
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/* 元素入队 */
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deque.pushLast(4)
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println("元素 4 队尾入队后 deque = ${deque.toArray().contentToString()}")
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deque.pushFirst(1)
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println("元素 1 队首入队后 deque = ${deque.toArray().contentToString()}")
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/* 元素出队 */
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val popLast = deque.popLast()
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println("队尾出队元素 = ${popLast},队尾出队后 deque = ${deque.toArray().contentToString()}")
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val popFirst = deque.popFirst()
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println("队首出队元素 = ${popFirst},队首出队后 deque = ${deque.toArray().contentToString()}")
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/* 获取双向队列的长度 */
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val size = deque.size()
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println("双向队列长度 size = $size")
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/* 判断双向队列是否为空 */
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val isEmpty = deque.isEmpty()
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println("双向队列是否为空 = $isEmpty")
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}
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