携程2019校招编程题（3）

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
//携程3
public class LRU {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int size=Integer.valueOf(sc.nextLine()) ;
        List<Integer> list1 = new ArrayList<>();//存key
        List<Integer> list2 = new ArrayList<>();//存value
        while(sc.hasNext()){
            String line =sc.nextLine();
            String[] subLine=line.split(" ");
            if(subLine[0].equals("p")){
                if(list1.contains(Integer.valueOf(subLine[1]))){//如果已经存在，只是将value改变
                    int k=list1.indexOf(Integer.valueOf(subLine[1]));
                    list2.set(k,Integer.valueOf(subLine[2]));
                }else{//否则放入队列尾
                    if(list1.size()>=size){
                        list1.remove(0);
                        list2.remove(0);
                    }
                    list1.add(Integer.valueOf(subLine[1]));
                    list2.add(Integer.valueOf(subLine[2]));
                }
                
            }else{//如果获取值
                
                if(list1.contains(Integer.valueOf(subLine[1]))){
                    int n =list1.indexOf(Integer.valueOf(subLine[1]));
                    
                    System.out.println(list2.get(n));
                    int key=list1.get(n);
                    int value = list2.get(n);
                    list2.remove(n);
                    list1.remove(n);
                    list1.add(key);
                    list2.add(value);
                    
                }else{
                    System.out.println(-1);
                }
            }
        }
        sc.close();
    }

}