数据结构：Stack

// Stack.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>
#include <stdio.h>
#include <string>
using namespace std;
//这里用的是链表节点实现的Node
struct DataNode
{
    int data;
    DataNode* prev;
    DataNode() {
        prev = nullptr;
    }
};
class Stack
{
public:
    Stack() :size(0) {}
    void Push(int val) {
        if (root == nullptr)
        {
            root = new DataNode();
            root->data = val;
            cur = root;
            minVal = val;
        }
        else {
            DataNode* node = new DataNode();
            node->prev = cur;
            node->data = val;
            cur = node;
            size++;
            if (minVal > val)
            {
                minVal = val;
            }
        }
    }
    void Pop() {
        if (cur->prev != nullptr)
        {
            DataNode* d = cur->prev;
            delete cur;
            cur = d;
            size--;
        }
    }
    int Top() { return cur->data; }
    int Size() {
        return size;
    }
    int Min() {
        int min_val = cur->data;
        DataNode* node = cur;
        while (node != nullptr)
        {
            if (min_val > node->data)
            {
                min_val = node->data;
            }
            node = node->prev;
        }
        return min_val;
    }
private:
    int minVal;
    DataNode* root;    //当前栈底节点
    DataNode* cur;    //当前top节点
    int size;
};

int main()
{
    Stack s;
    s.Push(5);
    s.Push(6);
    s.Push(7);
    s.Push(3);
    s.Push(1);
    printf("top:%d,min:%d,size:%d", s.Top(), s.Min(), s.Size());
    // 5 6 7 3 1
    string line;
    cout << "0 pop 1 print 2 min" << endl;
    while (line != "exit")
    {
        cin >> line;
        //getline(cin, line);
        if (line == "0")
        {
            s.Pop();
            printf("top:%d,min:%d,size:%d",s.Top(), s.Min(), s.Size());
        }
        if (line == "1")
        {
            cout << "top" << s.Top() << endl;
            printf("top:%d,min:%d,size:%d",s.Top(), s.Min(), s.Size());
        }
        if (line == "2")
        {
            cout << "Min" << s.Min() << endl;
        }
    }

    return 0;
}