Leetcode-最小栈

32.最小栈

题目内容：

代码及思路：

class MinStack {
public:
    /** initialize your data structure here. */
    //设置两个栈，一个用来存储数据，一个用来存储当前最小值
    MinStack() {
        
    }
    
    void push(int x) {
         s1.push(x);
         if(s2.empty()||x<=getMin())
             s2.push(x);
    }
    
    void pop() {
        if(s1.top()==getMin())
            s2.pop();
        s1.pop();
    }
    
    int top() {
        return s1.top();
    }
    
    int getMin() {
        return s2.top();
    }
    private:
        stack<int> s1; //保存所有的数据
        stack<int> s2; //保存当前最小值
};

/**
 * Your MinStack object will be instantiated and called as such:
 * MinStack* obj = new MinStack();
 * obj->push(x);
 * obj->pop();
 * int param_3 = obj->top();
 * int param_4 = obj->getMin();
 */