分条件出栈

import java.util.*;

public class CatDogAsylum {
    public ArrayList<Integer> asylum(int[][] ope) {
        // write code here
        ArrayList<Integer> res =new ArrayList<Integer>();
        Deque<Integer> deque = new ArrayDeque<Integer>();
        for(int i = 0;i<ope.length;i++){
            if(ope[i][0]==1)deque.add(ope[i][1]);
            if(ope[i][0]==2){
                if(deque.isEmpty()) continue;
                if(ope[i][1]==0){
                    res.add(deque.poll());
                }
                if(ope[i][1]==1){
                    if(deque.peekFirst()>0) res.add(deque.poll());
                    else{
                        Stack<Integer> stack = new Stack<Integer>();
                        while(!deque.isEmpty() && deque.peekFirst()<0){
                            stack.push(deque.pollFirst());
                        }
                        if(!deque.isEmpty()) res.add(deque.pollFirst());
                        while(!stack.isEmpty()){
                            deque.addFirst(stack.pop());
                        }
                    }
                }
                if(ope[i][1]==-1){
                    if(deque.peekFirst()<0) res.add(deque.poll());
                    else{
                        Stack<Integer> stack = new Stack<Integer>();
                        while( !deque.isEmpty() && deque.peekFirst()>0){
                            stack.push(deque.pollFirst());
                        }
                        if(!deque.isEmpty()) res.add(deque.pollFirst());
                        while(!stack.isEmpty()){
                            deque.addFirst(stack.pop());
                        }
                    }
                }
            }
        }
        return res;
    }
}

求解惑...问题在哪
public ArrayList asylum(int[][] ope) {
        // write code here
        ArrayList list = new ArrayList();
        ArrayList resList = new ArrayList();
        for(int i=0;i<ope.length;i++){
            if(ope[i][0]==1)
                list.add(ope[i][1]);
            if(ope[i][0]==2){
                if(!list.isEmpty()){
                    if(ope[i][1]==0){        
                        resList.add(list.get(0));
                        list.remove(0);                        
                    }
                    if(ope[i][1]==1){            
                        int index = list.indexOf(1);
                        if(index!=-1){
                            resList.add(list.get(index));
                            list.remove(index);
                        }
                    }
                    if(ope[i][1]==-1){
                        int index = list.indexOf(-1);
                        if(index!=-1){
                            resList.add(list.get(index));
                            list.remove(index);
                        }
                    }
                }    
            }
        }
        return resList;
    }

import java.util.ArrayList;
import java.util.LinkedList;

public class CatDogAsylum {
    public ArrayList<Integer> asylum(int[][] ope) {
        LinkedList<int[]> list = new LinkedList<>();
        ArrayList<Integer> res = new ArrayList<>();
        for (int[] items : ope) {

            if (items[0] == 1) {
                // 如果遇到宠物就加入列表中(收容所)
                list.add(items);
            } else if (items[0] == 2) {
                // 如果遇到收养人
                // 采取第一种收养方式
                if (items[1] == 0) {
                    if (!list.isEmpty()) {
                        int[] animal = list.remove(0);
                        res.add(animal[1]);
                    }
                } else {
                    // 收取猫或狗(若为1，则指定收养狗，若为-1则指定收养猫)
                    for (int i = 0; i < list.size(); i++) {
                        // 收容所有合适宠物则弹出
                        if ((items[1] == 1 && list.get(i)[1] > 0) || (items[1] == -1 && list.get(i)[1] < 0)) {
                            // 移除宠物
                            int[] animal = list.remove(i);
                            res.add(animal[1]);
                            // 结束本层循环
                            break;
                        }
                    }
                }
            }
        }
        return res;
    }
}

思路：只需要用一个额外的list就可以实现操作。
1  当为有动物进入收容所模式的时候，就直接用list存储对应的猫或狗.
   (list集合add属性是先存储的数放在index索引最小处)。
2  当为有人收养动物的时候：
    1) 直接收养最早的：即收养list中index索引最小的数；
    2)领养最早进入收容所的狗：从list中最小的index索引遍历大于0的数(表示狗)并添加即可；
    3)领养最早进入收容所的猫：从list中最小的index索引遍历小于0的数(表示猫)并添加即可；

code如下；

import java.util.*;

public class CatDogAsylum {
    public static ArrayList<Integer> asylum(int[][] ope) {
	       
		  ArrayList<Integer> list = new ArrayList<Integer>();
		  ArrayList<Integer> tempList = new ArrayList<Integer>();		  
		  int len = ope.length;//操作次数
                    
		  for(int i = 0; i < len; i++){			  
			  if(ope[i][0] == 1){
				  //第二个数为0则为不合法操作，如(1,1)代表收养狗，(1,-4)代表收养猫；(1,0)无操作
				  if(ope[i][1] != 0){
					  tempList.add(ope[i][1]);
				  }
			  }
			  if(ope[i][0] == 2){
				  int tempListSize = tempList.size();
				  int index = 0;
				  //获取最早的收养动物
				  if(ope[i][1] == 0){
					  list.add(tempList.get(0));
					  tempList.remove(0);
				  }else if(ope[i][1] == 1){//获取收养最早的狗
					  while(index < tempListSize){
						  //tempList中放入最早的数即为index最小的数
						  int dog = tempList.get(index);
						  if(dog > 0){
							  list.add(dog);
							  tempList.remove(index);
							  break;
						  }
						  index++;
					  }
				  }else{//获取最早的猫
					  while(index < tempListSize){
						  int cat = tempList.get(index);
						  if(cat < 0){
							  list.add(cat);
							  tempList.remove(index);
							  break;
						  }
						  index++;
					  }
				  }
			  }
			  
			  
		  }
		  
		  return list;
	        
	    }
	  
}