题解 | #栈的压入、弹出序列#

import java.util.ArrayList;

public class Solution {
    public boolean IsPopOrder(int [] pushA,int [] popA) {
        if(pushA.length == 0 && popA.length == 0){
            return true;
        }
        
        if(pushA.length == 0 || popA.length == 0){
            return false;
        }
        
        int[] temp = new int[pushA.length];
        
        int pushIndex = 0;
        int tempIndex = -1;
        int popIndex = 0;
        for(; popIndex < popA.length; ){
            
            if(tempIndex >= 0 && temp[tempIndex] == popA[popIndex]){
                // 模拟弹出操作
                temp[tempIndex] = 1001;
                tempIndex--;
                popIndex++;
                
            } else if(pushIndex < pushA.length) {
                for(; pushIndex < pushA.length;){
                    
                    // 模拟压入操作
                    tempIndex++;
                    temp[tempIndex] = pushA[pushIndex];
                    pushIndex++;

                    // 判断是否压入到目标值
                    if(temp[tempIndex] == popA[popIndex]){
                        break;
                    }
                }
            } else{
                // 不匹配目标值，且无可以继续压入的数据
                return false;
            }
            
        }
        
        return temp[0] == 1001;
    }
}