在Java中使用数组创建循环队列
如果在队列中输入的名称超过3个,则该队列将生成错误:在Java中使用数组创建循环队列,java,arrays,queue,Java,Arrays,Queue,如果在队列中输入的名称超过3个,则该队列将生成错误: Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 3 at hotelobjects.Queue.addqueue(Queue.java:17) at hotelobjects.HotelObjects.addCustomers(HotelObjects.java:82) at hotelobjects.HotelObjects.m
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 3
at hotelobjects.Queue.addqueue(Queue.java:17)
at hotelobjects.HotelObjects.addCustomers(HotelObjects.java:82)
at hotelobjects.HotelObjects.main(HotelObjects.java:44)
Java Result: 1
我如何确保在原始3之后输入的任何名称都将以循环方式放置在队列的前面
package hotelobjects;
import java.util.*;
import java.io.*;
public class HotelObjects {
static Queue myQueue = new Queue();
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws Exception {
String command;
Scanner input = new Scanner(System.in);
Room[] myHotel = new Room[10];
for (int x = 0; x < myHotel.length; x++) {
myHotel[x] = new Room();
}
System.out.println("10 Rooms Created");
while (true) {
System.out.print("\nEnter command or 'X' to exit: ");
command = input.next();
command = command.toLowerCase();
if (command.charAt(0) == 'x') {
System.exit(0);
}
if (command.charAt(0) == 'a') {
addCustomers(myHotel);
}
if (command.charAt(0) == '3') {
displayNames(myHotel);
}
}
}
private static void addCustomers(Room myHotel[]) {
String roomName;
int roomNum;
System.out.println("Enter room number (0-10) or 11 to exit:");
Scanner input = new Scanner(System.in);
roomNum = input.nextInt();
if (roomNum<11) {
System.out.println("Enter name for room " + roomNum + " :");
roomName = input.next();
roomName = roomName.toLowerCase();
myHotel[roomNum].setName(roomName);
myQueue.addqueue(roomName);
}
else {
System.exit(0);
}
}
private static void displayNames(Room[] myHotel) {
System.out.println("The last 3 names entered are: ");
for (int x = 0; x < 3; x++) {
myQueue.takequeue();
}
}
}
增加索引模块队列中元素的最大数量:
void addqueue(String roomName) {
qitems[end] = roomName;
end = (end + 1) % 3;
}
所以你得到:
end = (0 + 1) % 3 = 1
end = (1 + 1) % 3 = 2
end = (2 + 1) % 3 = 0
end = (0 + 1) % 3 = 1
...
您还应该更改<代码> ToeQueWe()/Cux>方法来考虑队列现在是循环的事实。大概是这样的:
void takequeue() {
System.out.println("Name Entered : " + qitems[front]);
front = (front + 1) % 3;
}
最好创建一个常数来存储队列容量,而不是在整个代码中重复3
值:
private static final int CAPACITY = 3;
我尝试添加您的更改,但队列现在会删除原始名称。循环队列就是这样工作的。如果需要在队列中存储更多元素,则需要增加其容量。问题出在
takequeue()
中。我更新了答案,希望有帮助。
private static final int CAPACITY = 3;