622. Design Circular Queue
作者:互联网
package LeetCode_622 /** * 622. Design Circular Queue * https://leetcode.com/problems/design-circular-queue/description/ * * Your implementation should support following operations: MyCircularQueue(k): Constructor, set the size of the queue to be k. Front: Get the front item from the queue. If the queue is empty, return -1. Rear: Get the last item from the queue. If the queue is empty, return -1. enQueue(value): Insert an element into the circular queue. Return true if the operation is successful. deQueue(): Delete an element from the circular queue. Return true if the operation is successful. isEmpty(): Checks whether the circular queue is empty or not. isFull(): Checks whether the circular queue is full or not. * */ class MyCircularQueue(k: Int) { var array: IntArray? = null var size = 0 var currentSize = 0 var front = -1 //rear always pointed to the available location where can insert new data var rear = -1 /** Initialize your data structure here. Set the size of the queue to be k. */ init { this.size = k array = IntArray(size) } /** Insert an element into the circular queue. Return true if the operation is successful. */ fun enQueue(value: Int): Boolean { if (isFull()) { return false } rear = (rear + 1) % size //for example: 2%5=2, -2%5=-2, 2%-5=2 array!![rear] = value currentSize++ if (front == -1) { front = rear } return true } /** Delete an element from the circular queue. Return true if the operation is successful. */ fun deQueue(): Boolean { if (isEmpty()) { return false } //move the front to next //val deQeueuElement = array!![front] array!![front] = -1 front = (front + 1) % size currentSize-- return true } /** Get the front item from the queue. */ fun Front(): Int { return if (isEmpty()) -1 else array!![front] } /** Get the last item from the queue. */ fun Rear(): Int { return if (isEmpty()) -1 else array!![rear] } /** Checks whether the circular queue is empty or not. */ fun isEmpty(): Boolean { return currentSize == 0 } /** Checks whether the circular queue is full or not. */ fun isFull(): Boolean { return currentSize == array?.size } } /** * Your MyCircularQueue object will be instantiated and called as such: * var obj = MyCircularQueue(k) * var param_1 = obj.enQueue(value) * var param_2 = obj.deQueue() * var param_3 = obj.Front() * var param_4 = obj.Rear() * var param_5 = obj.isEmpty() * var param_6 = obj.isFull() */
标签:622,return,queue,Queue,var,Design,front,size,circular 来源: https://www.cnblogs.com/johnnyzhao/p/12597887.html