155. 最小栈（C++题解含VS可运行源程序）

1.题解

辅助栈

使用辅助栈：两个辅助栈（一个数据栈，一个最小值栈）

2.力扣C++源码

class MinStack {
public:
    MinStack() {

    }
    
    void push(int val) {
        s1.push(val);
        if (minS.empty() || minS.top() >= val) {
            minS.push(val);
        }
    }

    void pop() {
        if (minS.top() == s1.top())
            minS.pop();
        s1.pop();
    }

    int top() {
        return s1.top();
    }

    int getMin() {
        return minS.top();
    }
    //使用辅助栈
    stack<int> s1, minS;
};

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

3.VS可运行源程序

#include<stdio.h>
#include<stdlib.h>
#include<iostream>
#include<vector>
#include<queue>
#include<stack>
#include<limits>
#include<algorithm>
#include<math.h>
#pragma warning(disable:4996)
using namespace std;

//使用辅助栈：两个辅助栈（一个数据栈，一个最小值栈）
class MinStack {
public:
    MinStack() {

    }

    void push(int val) {
        s1.push(val);
        if (minS.empty() || minS.top() >= val) {
            minS.push(val);
        }
    }

    void pop() {
        if (minS.top() == s1.top())
            minS.pop();
        s1.pop();
    }

    int top() {
        return s1.top();
    }

    int getMin() {
        return minS.top();
    }
    //使用辅助栈
    stack<int> s1, minS;
};

/**
 * Your MinStack object will be instantiated and called as such:
 * MinStack* obj = new MinStack();
 * obj->push(val);
 * obj->pop();
 * int param_3 = obj->top();
 * int param_4 = obj->getMin();
 */
int main()
{
    MinStack* obj = new MinStack();
    obj->push(-2);
    obj->push(0);
    obj->push(-3);
    printf("此时栈中最小值为：%d\n", obj->getMin());
    obj->pop();
    printf("此时栈顶元素为：%d\n", obj->top());
    printf("此时栈中最小值为：%d", obj->getMin());

	printf("\n");
	system("pause");
	return 0;
}