杨.md

import java.util.ArrayList;
import java.util.Stack;

public class Solution {
    public boolean IsPopOrder(int [] pushA,int [] popA) {
        if(pushA.length == 1 && popA.length==1){
            if(pushA[0] == popA[0]){
                return true;
            }else {
                return false;
            }
        }
        Stack<Integer> stack = new Stack<>();
        ArrayList<Integer> list = new ArrayList<>();
        for (int push : pushA){
            list.add(push);
        }
        for(int pop : popA){
            if(!stack.isEmpty() && pop == stack.peek()){
                stack.pop();
                continue;
            }else if (!stack.isEmpty() && stack.contains(pop)){
                return false;
            }else {
                int index = list.indexOf(pop);
                for(int i=0;i<index;i++){
                    if((Integer) list.get(i)!=null){
                        stack.push((Integer) list.get(i));
                        list.set(i, null);
                    }
                }
                list.set(index,null);
            }
        }
        if(stack.isEmpty()){
            return true;
        }
        return false;
    }
}