环形队列
package com.cxy.springdataredis.data; import java.util.Scanner; public class CircleArray { public static void main(String[] args) { CirCleArrayQueue queue = new CirCleArrayQueue(4); boolean loop =true; char key ; Scanner scanner = new Scanner(System.in); while (loop) { System.out.println("s(show): 显示队列"); System.out.println("e(exit): 退出程序"); System.out.println("a(add): 添加数据到队列"); System.out.println("g(get): 从队列取出数据"); System.out.println("h(head): 查看队列头的数据"); key = scanner.next().charAt(0);// 接收一个字符 switch (key) { case 's': queue.showQueue(); break; case 'a': System.out.println("输出一个数"); int value = scanner.nextInt(); queue.addQueue(value); break; case 'g': // 取出数据 try { int res = queue.getQueue(); System.out.printf("取出的数据是%d\n", res); } catch (Exception e) { // TODO: handle exception System.out.println(e.getMessage()); } break; case 'h': // 查看队列头的数据 try { int res = queue.getHeader(); System.out.printf("队列头的数据是%d\n", res); } catch (Exception e) { // TODO: handle exception System.out.println(e.getMessage()); } break; case 'e': // 退出 scanner.close(); loop = false; break; default: break; } } System.out.println("程序退出~~"); } } class CirCleArrayQueue{ private int maxSize; //表示数组的第一个元素,初始化0 private int font; //表示数组的最后一个元素的最后一个位置 private int rear; private int[] arr; public CirCleArrayQueue(int arrMaxSize){ maxSize =arrMaxSize; arr =new int[maxSize]; font =0; rear =0; } public boolean isFull(){ return (rear+1)%maxSize ==font; } public boolean isEmpty(){ return font ==rear; } public void addQueue(int n){ if (isFull()){ System.out.println("队列已经满了"); return ; } arr[rear] =n; //将rear后移必须考虑取模 rear =(rear+1)%maxSize; } public int getQueue(){ if (isEmpty()){ throw new RuntimeException("队列为空"); } int value =arr[font]; font =(font+1)%maxSize; return value; } public void showQueue(){ if (isEmpty()){ System.out.println("队列为空"); return ; } for (int i =font;i<font+getSize();i++){ System.out.printf("arr[%d]=%d\n",i%maxSize,arr[i%maxSize]); } } public int getSize(){ return (rear+maxSize-font)%maxSize; } public int getHeader(){ if (isEmpty()){ throw new RuntimeException("队列为空"); } return arr[font]; } }
笔记转移,由于在有道云的笔记转移,写的时间可能有点久,如果有错误的地方,请指正