用java实现循环队列？

用java实现循环队列？

class Element{
int id;
String name;
Element(int a,String n){
id=a;name=n;
}
}

class SeqQueue{
int first,last,maxsize;
Element queue[];
SeqQueue(int i){
maxsize=i;
first=last=-1;
queue=new Element[i];
}

public void clear(){//置空
first=last=-1;
}

public boolean isEmpty(){//判空
if(first==-1)return true;
else return false;
}

public Element getFirst(){//取队列头元素
if(first==-1)return null;
else return queue[first+1];
}

public boolean isFull(){//判满
if((last+1)%maxsize==first)return true;
else return false;
}

public boolean enQueue(Element e){//入队
if(this.isFull())return false;
if(this.isEmpty())
first=last=0;
else
last=(last+1)%maxsize;
queue[last]=e;
return true;
}

public Element deQueue(){//出队
Element t=queue[first];
if(this.isEmpty())return null;
if(first==last){
queue[first]=null;
this.clear();
return t;
}
queue[first]=null;
first=(first+1)%maxsize;
return t;
}

public int getLength(){//队列长度
if(last>=first)return last-first+1;
else return maxsize-(first-last)+1;
}

public void display(){//打印所有元素
int i,j;
for (i=first,j=0;j<this.getLength();i=(i+1)%maxsize,j++)
System.out.println(queue[i].id);
}
}2007-10-29

简单写了下，希望你能看明白

import java.util.ArrayList;

public class SeqQueue {

ArrayList<String> list;

public SeqQueue() {
list = new ArrayList<String>();
}

public String getFirst() {
if (!list.isEmpty()) {
String s = list.get(0);
list.remove(0);
return s;
}
return null;
}

public void insertLast(String s) {
list.add(s);
}

public static void main(String[] args) {
SeqQueue seq = new SeqQueue();
seq.insertLast("111");
seq.insertLast("222");
seq.insertLast("333");
System.out.println(seq.getFirst());
System.out.println(seq.getFirst());
System.out.println(seq.getFirst());
}

}2007-11-02

你有数据结构这本书吗。自己慢慢看去。上面有的。一模一样的原题。2007-10-28