AcWing 42. 栈的压入、弹出序列（C++）- 栈、模拟

题目链接：https://www.acwing.com/problem/content/description/40/
题目如下：

class Solution {
    
    
public:
    bool isPopOrder(vector<int> pushV,vector<int> popV) {
    
    
        //两种情况的特判
        if(pushV.size()==0&&popV.size()==0) return true;
        if(pushV.size()!=popV.size()) return false;
        
        stack<int> stk;
        int index=0;
        for(int i=0;i<pushV.size();i++){
    
    
            stk.push(pushV[i]);
            
            while(!stk.empty()&&stk.top()==popV[index]){
    
    //只要栈中还有元素，遇到相同的就弹出，遇不到相同的存入
                stk.pop();
                ++index;
            }
        }
        
        return stk.empty();
    }
};