算法系列之-猫狗队列

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package it.stack;

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

/**
 * @项目名称：util
 * @类名称：DogCatQueue @类描述： 猫狗队列，实现的方法有添加，猫出，狗出，是否为空，等。
 *
 * @author 赵建银
 * @date 2017年12月27日
 * @time 下午6:08:03
 * @version 1.0
 */
public class DogCatQueue {

    private Queue<PetEnter> dogQ;
    private Queue<PetEnter> catQ;
    private long count;

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

    public void add(Pet pet) {
        if (pet.getType().equals("dog")) {
            PetEnter petEnter = new PetEnter(pet, this.count++);
            dogQ.add(petEnter);
        } else if (pet.getType().equals("cat")) {
            PetEnter petEnter = new PetEnter(pet, this.count++);
            catQ.add(petEnter);
        } else {
            throw new RuntimeException("类型不匹配");
        }
    }

    /**
     * 注意：当某个队列为空时将剩下的队列全部按顺序poll
     * 
     * @return
     */
    public Pet pollAll() {
        if (this.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.catQ.poll().getPet();
        } else if (this.catQ.isEmpty()) {
            return this.dogQ.poll().getPet();
        } else {
            throw new RuntimeException("queue is empty");
        }
    }

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

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

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

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

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

}

class Pet {
    private String type;

    public String getType() {
        return type;
    }

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

}

class Cat extends Pet {
    public Cat() {
        super("Cat");
    }
}

class Dog extends Pet {
    public Dog() {
        super("Dog");
    }
}

class PetEnter {
    private Pet pet;
    private long count;// 时间戳

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

    public Pet getPet() {
        return pet;
    }

    public long getCount() {
        return count;
    }
}