实现一个栈，带求min元素功能-优快云博客

本文介绍了一个使用C++实现的特殊栈类——最小值栈。该栈可以在常数时间内获取栈内最小值，通过维护一个额外的数据结构跟踪每次入栈时的最小值信息，实现了高效的最小值查询功能。

/*
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 */

/* 
 * File:   main.cpp
 * Author: Administrator
 *
 * Created on 2017年5月2日, 下午10:52
 */

#include <cstdlib>
#include <stack>
#include <vector>
#include <iostream>
using namespace std;

/*
 * 
 */

template <typename T>
class min_stack
{
    struct dataType
    {
        T data;
        unsigned index;//用于记录最小元素的下标
        dataType():data(),index(0xFFFFFFFF){}
        dataType(T d, unsigned i):data(d),index(i){}
    };
    
    private:
        vector<dataType> _m_stack;
        unsigned _min;//记录当前栈顶最小元素的索引
        
    public:
        min_stack():_m_stack(),_min(0xFFFFFFFF) {}
        ~min_stack();
        void push(T data);
        void pop();
        T min();
};

template <typename T>
min_stack<T>::~min_stack()
{}

template <typename T>
void min_stack<T>::push(T data)
{
    _m_stack.push_back(dataType(data, _min));
    if (0xFFFFFFFF == _min)
    {
        _min = 0;
        return;
    }
    
    if (data < _m_stack[_min].data)
    {
        _min = _m_stack.size() - 1;
        return;
    }
}

template <typename T>
void min_stack<T>::pop()
{
    if (0 == _m_stack.size()) return;
    _min = (_m_stack.back()).index;
    _m_stack.pop_back();
}

template <typename T>
T min_stack<T>::min()
{
    return _m_stack[_min].data;
}

int main(int argc, char** argv) {
    
    int min;
    min_stack<int> test;
    test.push(4);  
    test.push(5);  
    test.push(7);  
    test.push(2);  
    min = test.min();  
    cout << min << endl;
    test.push(1);  
    min = test.min();  
    cout << min << endl;
    test.pop();  
    min = test.min();  
    cout << min << endl;
    test.pop();  
    min = test.min();  
    cout << min << endl;
    test.pop();  
    min = test.min();  
    cout << min << endl;
    test.pop();  
    min = test.min();  
    cout << min << endl;
    system("pause");  
    return 0;
}

转载于:https://my.oschina.net/mskk/blog/891885