数据结构Java实现07----队列：顺序队列&顺序循环队列、链式队列、顺序优先队列

1//栈接口
2publicinterfaceStack{
3
4//入栈
5publicvoidpush(Objectobj)throwsException;
6
7//出栈
8publicObjectpop()throwsException;
9
10//获得栈顶元素
11publicObjectgetTop()throwsException;
12
13//判断栈是否为空
14publicbooleanisEmpty();
15}

1publicclassLinkStackimplementsStack{
2
3Nodehead;//栈顶指针
4intsize;//结点的个数
5
6publicLinkStack(){
7head=null;
8size=0;
9}
10
11@Override
12publicObjectgetTop()throwsException{
13//TODOAuto-generatedmethodstub
14returnhead.getElement();
15}
16
17@Override
18publicbooleanisEmpty(){
19//TODOAuto-generatedmethodstub
20returnhead==null;
21}
22
23@Override
24publicObjectpop()throwsException{
25//TODOAuto-generatedmethodstub
26if(isEmpty()){
27thrownewException("栈为空！");
28}
29Objectobj=head.getElement();
30head=head.getNext();
31size--;
32returnobj;
33
34}
35
36@Override
37publicvoidpush(Objectobj)throwsException{
38//TODOAuto-generatedmethodstub
39head=newNode(obj,head);
40size++;
41}
42
43}

1publicclassTest{
2
3publicstaticvoidmain(String[]args)throwsException{
4
5Stringstr1="ABCDCBA";//是回文
6Stringstr2="ABCDECAB";//不是回文
7
8try{
9if(Test.isHuiWen(str1)){
10System.out.println(str2+":是回文！");
11}else{
12System.out.println(str2+":不是回文！");
13}
14}catch(Exceptionex){
15ex.printStackTrace();
16}
17}
18
19
20//方法：判断字符串是否回文
21publicstaticbooleanisHuiWen(Stringstr)throwsException{
22intn=str.length();
23LinkStackstack=newLinkStack();//创建堆栈
24LinkQueuequeue=newLinkQueue();//创建队列
25for(inti=0;i<n;i++){
26stack.push(str.subSequence(i,i+1));//把字符串每个字符压进堆栈
27queue.append(str.subSequence(i,i+1));//把字符串每个字符压入队列
28}
29while(!queue.isEmpty()&&!stack.isEmpty()){
30if(!queue.delete().equals(stack.pop())){//出队列，出栈，同时判断是否相同
31returnfalse;
32}
33}
34
35returntrue;
36}
37
38}

1//优先级队列元素类
2publicclassElement{
3
4privateObjectelement;//数据
5privateintpriority;//优先级
6
7publicElement(Objectobj,intpriority){
8this.element=obj;
9this.priority=priority;
10}
11
12publicObjectgetElement(){
13returnelement;
14}
15
16publicvoidsetElement(Objectelement){
17this.element=element;
18}
19
20publicintgetPriority(){
21returnpriority;
22}
23
24publicvoidsetPriority(intpriority){
25this.priority=priority;
26}
27
28}

1//队列接口
2publicinterfaceQueue{
3
4//入队
5publicvoidappend(Objectobj)throwsException;
6
7//出队
8publicObjectdelete()throwsException;
9
10//获得队头元素
11publicObjectgetFront()throwsException;
12
13//判断对列是否为空
14publicbooleanisEmpty();
15}

1//优先级队列
2publicclassPrioritySequenceQueueimplementsQueue{
3
4staticfinalintdefaultSize=10;//默认队列长度
5intfront;//队头
6intrear;//队尾
7intcount;//计数器
8intmaxSize;//队列最大长度
9Element[]queue;//队列
10
11publicPrioritySequenceQueue(){
12init(defaultSize);
13}
14
15publicPrioritySequenceQueue(intsize){
16init(size);
17}
18
19publicvoidinit(intsize){
20maxSize=size;
21front=rear=0;
22count=0;
23queue=newElement[size];
24}
25
26@Override
27publicvoidappend(Objectobj)throwsException{
28//TODOAuto-generatedmethodstub
29//如果队列已满
30if(count>=maxSize){
31thrownewException("队列已满！");
32}
33queue[rear]=(Element)obj;
34rear++;
35count++;
36}
37
38@Override
39publicObjectdelete()throwsException{
40//TODOAuto-generatedmethodstub
41if(isEmpty()){
42thrownewException("队列为空！");
43}
44//默认第一个元素为优先级最高的。
45Elementmin=queue[0];
46intminIndex=0;
47for(inti=0;i<count;i++){
48if(queue[i].getPriority()<min.getPriority()){
49min=queue[i];
50minIndex=i;
51}
52}
53
54//找的优先级别最高的元素后，把该元素后面的元素向前移动。
55for(inti=minIndex+1;i<count;i++){
56queue[i-1]=queue[i];//移动元素
57}
58rear--;
59count--;
60returnmin;
61}
62
63@Override
64publicObjectgetFront()throwsException{
65//TODOAuto-generatedmethodstub
66if(isEmpty()){
67thrownewException("队列为空！");
68}
69//默认第一个元素为优先级最高的。
70Elementmin=queue[0];
71intminIndex=0;
72for(inti=0;i<count;i++){
73if(queue[i].getPriority()<min.getPriority()){
74min=queue[i];
75minIndex=i;
76}
77}
78returnmin;
79}
80
81@Override
82publicbooleanisEmpty(){
83//TODOAuto-generatedmethodstub
84returncount==0;
85}
86
87}

1publicclassTest{
2
3publicstaticvoidmain(String[]args)throwsException{
4
5PrioritySequenceQueuequeue=newPrioritySequenceQueue();
6Elementtemp;
7
8//五个进程入队
9queue.append(newElement(1,30));
10queue.append(newElement(2,20));
11queue.append(newElement(3,40));
12queue.append(newElement(4,20));
13queue.append(newElement(5,0));
14
15//按照优先级出队。
16System.out.println("编号优先级");
17while(!queue.isEmpty()){
18temp=(Element)queue.delete();
19System.out.println(temp.getElement()+""+temp.getPriority());
20}
21}
22}