155.最小栈.cpp

/*
 * @lc app=leetcode.cn id=155 lang=cpp
 *
 * [155] 最小栈
 */

// @lc code=start
#include<iostream>
#include<stack>
#include<set>
#include<algorithm>
#include<climits>
#include<queue>
#include<vector>
using namespace std;

class MinStack {
public:
    /** initialize your data structure here. */

    stack<int> s1;
    stack<int> s2;
    MinStack() {
        
    }
    
    void push(int x) {
        s1.push(x);
        if(s2.empty()||s2.top()>=x){
            s2.push(x);
        }
    }
    
    void pop() {
        if(s1.top()==getMin()){
            s2.pop();
        }
        s1.pop();
    }
    
    int top() {
        return s1.top();
    }
    
    int getMin() {
        return s2.top();
    }
};

/**
 * 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();
 */
// @lc code=end