劍指 offer 計算棧中最小的數據

class Solution {//在這裏利用一個輔助棧來解決問題
public:
    void push(int value) {
        datastack.push(value);
        if (minstack.empty()){
            minstack.push(value);
        }
        if (value <= minstack.top()){
            minstack.push(value);
        }
        
    }
    void pop() {
        if (datastack.empty()){
            return;
        }
        if (minstack.top() == datastack.top() ){
            minstack.pop();
        }
        datastack.pop();
        
    }
    int top() {
        return datastack.top();
    }
    int min() {
        return minstack.top();
    }
 private:
    stack<int> datastack;
    stack<int> minstack;


};