猫狗队列

public class Pet { private String type; public Pet(String type) { this.type = type; } public String getPetType() { return this.type; } } public class Dog extends Pet { public Dog() { super("dog"); } } public class Cat extends Pet { public Cat() { super("cat"); } }
实现一种狗猫队列的结构，要求如下：用户可以调用add方法将cat类或dog类的实例放入队列中；用户可以调用pollAll方法，将队列中所有的实例按照进队列的先后顺序依次弹出；用户可以调用pollDog方法，将队列中dog类的实例按照进队列的先后顺序依次弹出；用户可以调用pollCat方法，将队列中cat类的实例按照进队列的先后顺序依次弹出；用户可以调用isEmpty方法，检查队列中是否还有dog或cat的实例；用户可以调用isDogEmpty方法，检查队列中是否有dog 类的实例；用户可以调用isCatEmpty方法，检查队列中是否有cat类的实例

  1 package my_basic.class_3;
  2 
  3 import java.util.LinkedList;
  4 import java.util.Queue;
  5 
  6 /*猫狗队列*/
  7 public class Code_04_CatDogQueue {
  8     public static class Pet{
  9         private String type;
 10 
 11         public Pet(String type) {
 12             this.type = type;
 13         }
 14         public  String getPetType() {
 15             return this.type;
 16         }
 17     }
 18     public static class Dog extends Pet{
 19         public Dog() {
 20             super("dog");
 21         }
 22     }
 23     public static class Cat extends Pet{
 24         public Cat() {
 25             super("cat");
 26         }
 27     }
 28     
 29     public static class PetEnterQueue{
 30         private Pet pet;
 31         private Integer count;
 32         
 33         public PetEnterQueue(Pet pet, Integer count) {
 34             this.pet = pet;
 35             this.count = count;
 36         }
 37         public Pet getPet() {
 38             return pet;
 39         }
 40         
 41         public Integer getCount() {
 42             return count;
 43         }
 44     }
 45     
 46     public static class DogCatQueue{
 47         private Queue<PetEnterQueue> dogQ;
 48         private Queue<PetEnterQueue> catQ;
 49         private int count =0 ;
 50         
 51         
 52         public DogCatQueue() {
 53             super();
 54             this.dogQ = new LinkedList<PetEnterQueue>();
 55             this.catQ = new LinkedList<PetEnterQueue>();
 56             this.count = 0;
 57         }
 58         
 59         public void add(Pet pet) {
 60             if (pet.getPetType().equals("dog")) {
 61                 this.dogQ.add(new PetEnterQueue(pet, this.count++));
 62             }else if (pet.getPetType().equals("cat")) {
 63                 this.catQ.add(new PetEnterQueue(pet, count++));
 64             }else {
 65                 throw new IllegalArgumentException("不是猫或狗");
 66             }
 67         }
 68         public Pet pollAll() {
 69             if (!dogQ.isEmpty() && !catQ.isEmpty()) {
 70                 if (this.dogQ.peek().getCount() < this.catQ.peek().getCount()) {
 71                     return dogQ.poll().getPet();
 72                 }else {
 73                     return catQ.poll().getPet();
 74                 }
 75             }else if (!dogQ.isEmpty()) {
 76                 return dogQ.poll().getPet();
 77             }else if (!catQ.isEmpty()) {
 78                 return catQ.poll().getPet();
 79             }else {
 80                 throw new RuntimeException("queue is empty!");
 81             }
 82         }
 83         public Pet pollDog() {
 84             if (!isDogEmpty()) {
 85                 return dogQ.poll().getPet();
 86             }
 87             throw new RuntimeException("dogQ is empty!" );
 88         }
 89         public Pet pollCat() {
 90             if (!isCatEmpty()) {
 91                 return catQ.poll().getPet();
 92             }
 93             throw new RuntimeException("dogQ is empty!" );
 94         }
 95         public boolean isEmpty() {
 96             return (dogQ.isEmpty() && catQ.isEmpty())? true : false;
 97         }
 98         public boolean isDogEmpty() {
 99             return dogQ.isEmpty();
100         }
101         public boolean isCatEmpty() {
102             return catQ.isEmpty();
103         }
104         
105     }
106     
107     /*for test*/
108     public static void main(String[] args) {
109         DogCatQueue test = new DogCatQueue();
110 
111         Pet dog1 = new Dog();
112         Pet cat1 = new Cat();
113         Pet dog2 = new Dog();
114         Pet cat2 = new Cat();
115         Pet dog3 = new Dog();
116         Pet cat3 = new Cat();
117 
118         test.add(dog1);
119         test.add(cat1);
120         test.add(dog2);
121         test.add(cat2);
122         test.add(dog3);
123         test.add(cat3);
124 
125         test.add(dog1);
126         test.add(cat1);
127         test.add(dog2);
128         test.add(cat2);
129         test.add(dog3);
130         test.add(cat3);
131 
132         test.add(dog1);
133         test.add(cat1);
134         test.add(dog2);
135         test.add(cat2);
136         test.add(dog3);
137         test.add(cat3);
138         while (!test.isDogEmpty()) {
139             System.out.println(test.pollDog().getPetType());
140         }
141         while (!test.isEmpty()) {
142             System.out.println(test.pollAll().getPetType());
143         }
144     }
145 
146 }