牛客剑指offer，栈的压入弹出

class Solution {
public:
    bool IsPopOrder(vector<int> pushV,vector<int> popV) {
        bool bPossible =false;
        int nLength = pushV.size();
        if(!pushV.empty() && !popV.empty() && nLength > 0)
        {
            int i = 0;
            int j = 0;
            stack<int> s1;
            while(j< nLength-1)
            {
                while(s1.empty()||s1.top()!=popV[j])
                {
                    if(i== nLength-1)
                    {
                        break;
                    }
                    s1.push(pushV[i]);
                    i++;
                }
                if(s1.top()!= popV[j])
                    break;
                s1.pop();
                j++;
            }
            if(s1.empty() && j == nLength-1)
                bPossible = true;
        }
        return bPossible;
    }
};