算法-猫狗队列

猫狗队列

题目如下：

代码如下：

package com.jujuxiaer.zuoshen2018.class_03;

import java.util.LinkedList;
import java.util.Queue;

public class Code_04_DogCatQueue {

	public static class Pet {
		private String type;
		private String petName;

		public Pet(String type, String petName) {
			this.type = type;
			this.petName = petName;
		}

		public String getPetType() {
			return this.type;
		}

		public String getPetName() {
			return petName;
		}
	}

	public static class Dog extends Pet {
		public Dog(String dogName) {
			super("dog", dogName);
		}
	}

	public static class Cat extends Pet {
		public Cat(String catName) {
			super("cat", catName);
		}
	}

	/**
	 * 宠物进-队列
	 * 表示宠物加上个时间戳的实体
	 */
	public static class PetEnter {
		private Pet pet;
		private long count;

		public PetEnter(Pet pet, long count) {
			this.pet = pet;
			this.count = count;
		}

		public Pet getPet() {
			return this.pet;
		}

		public long getCount() {
			return this.count;
		}

		public String getEnterPetType() {
			return this.pet.getPetType();
		}
	}

	public static class DogCatQueue {
		private Queue<PetEnter> dogQ;
		private Queue<PetEnter> catQ;
		private long count;

		public DogCatQueue() {
			this.dogQ = new LinkedList<>();
			this.catQ = new LinkedList<>();
			this.count = 0;
		}

		public void add(Pet pet) {
			if (pet.getPetType().equals("dog")) {
				this.dogQ.add(new PetEnter(pet, this.count++));
			} else if (pet.getPetType().equals("cat")) {
				this.catQ.add(new PetEnter(pet, this.count++));
			} else {
				throw new RuntimeException("err, not dog or cat");
			}
		}

		public Pet pollAll() {
			if (!this.dogQ.isEmpty() && !this.catQ.isEmpty()) {
				if (this.dogQ.peek().getCount() < this.catQ.peek().getCount()) {
					return this.dogQ.poll().getPet();
				} else {
					return this.catQ.poll().getPet();
				}
			} else if (!this.dogQ.isEmpty()) {
				return this.dogQ.poll().getPet();
			} else if (!this.catQ.isEmpty()) {
				return this.catQ.poll().getPet();
			} else {
				throw new RuntimeException("err, queue is empty!");
			}
		}

		public Dog pollDog() {
			if (!this.isDogQueueEmpty()) {
				return (Dog) this.dogQ.poll().getPet();
			} else {
				throw new RuntimeException("Dog queue is empty!");
			}
		}

		public Cat pollCat() {
			if (!this.isCatQueueEmpty()) {
				return (Cat) this.catQ.poll().getPet();
			} else {
				throw new RuntimeException("Cat queue is empty!");
			}
		}

		public boolean isEmpty() {
			return this.dogQ.isEmpty() && this.catQ.isEmpty();
		}

		public boolean isDogQueueEmpty() {
			return this.dogQ.isEmpty();
		}

		public boolean isCatQueueEmpty() {
			return this.catQ.isEmpty();
		}

	}

	public static void main(String[] args) {
		DogCatQueue dogCatQueue = new DogCatQueue();

		Pet dog1 = new Dog("dog1");
		Pet cat1 = new Cat("cat1");

		Pet dog2 = new Dog("dog2");
		Pet cat2 = new Cat("cat2");

		Pet dog3 = new Dog("dog3");
		Pet cat3 = new Cat("cat3");

		dogCatQueue.add(dog1);
		dogCatQueue.add(cat1);
		dogCatQueue.add(dog2);
		dogCatQueue.add(cat2);
		dogCatQueue.add(dog3);
		dogCatQueue.add(cat3);

		dogCatQueue.add(dog1);
		dogCatQueue.add(cat1);
		dogCatQueue.add(dog2);
		dogCatQueue.add(cat2);
		dogCatQueue.add(dog3);
		dogCatQueue.add(cat3);

		dogCatQueue.add(dog1);
		dogCatQueue.add(cat1);
		dogCatQueue.add(dog2);
		dogCatQueue.add(cat2);
		dogCatQueue.add(dog3);
		dogCatQueue.add(cat3);
		while (!dogCatQueue.isDogQueueEmpty()) {
			System.out.println(dogCatQueue.pollDog().getPetName());
		}
		
		while (!dogCatQueue.isCatQueueEmpty()) {
			System.out.println(dogCatQueue.pollCat().getPetName());
		}
		
		while (!dogCatQueue.isEmpty()) {
			System.out.println(dogCatQueue.pollAll().getPetName());
		}
	}

}

下面代码的结果输出为：
    while (!dogCatQueue.isDogQueueEmpty()) {
        System.out.println(dogCatQueue.pollDog().getPetName());
    }

输出：
    dog1
    dog2
    dog3
    dog1
    dog2
    dog3
    dog1
    dog2
    dog3

下面代码的结果输出为：
    while (!dogCatQueue.isCatQueueEmpty()) {
        System.out.println(dogCatQueue.pollCat().getPetName());
    }
输出：
    cat1
    cat2
    cat3
    cat1
    cat2
    cat3
    cat1
    cat2
    cat3

下面代码的结果输出为：
    while (!dogCatQueue.isEmpty()) {
        System.out.println(dogCatQueue.pollAll().getPetName());
    }
输出：
    dog1
    cat1
    dog2
    cat2
    dog3
    cat3
    dog1
    cat1
    dog2
    cat2
    dog3
    cat3
    dog1
    cat1
    dog2
    cat2
    dog3
    cat3