stack--oj1

链接: link

class MinStack {
public:
    MinStack() {

    }

    void push(int val) {
        st1.push(val);
        if (st2.size())
        {
            if (st2.top() >= val)
            {
                st2.push(val);
            }

        }
        else
            st2.push(val);

    }

    void pop() {
        int a=st1.top();
        st1.pop();
        if (a == st2.top())
        {
            st2.pop();
        }

    }

    int top() {
        return st1.top();
    }

    int getMin() {
        return st2.top();
    }
private:
    stack<int> st1;
    stack<int> st2;
};

链接: [link]
(https://www.youkuaiyun.com/https://www.nowcoder.com/practice/d77d11405cc7470d82554cb392585106?tpId=13&&tqId=11174&rp=1&ru=/activity/oj&qru=/ta/coding-interviews/question-ranking)

class Solution {
public:

    bool IsPopOrder(vector<int>& pushV, vector<int>& popV) {
        stack<int> st1;
        int pushi = 0, popi = 0;
        while (pushi<pushV.size())
        {
            st1.push(pushV[pushi++]);
            while(!st1.empty()&&st1.top() == popV[popi])
            {
                st1.pop();
                popi++;
            }
        }
        return st1.empty();
    }
};