#include <map>

//tuple多元数组，必须是静态数组，类似结构体

//配合array，vector使用

//std::tuple<数组元素类型>数组变量名(数组元素变量名);

#include <iostream>
#include <map>
using namespace std;

//tuple多元数组，必须是静态数组，类似结构体
//配合array，vector使用

void main()
{
    int int1(10);
    double double1(99.8);
    char ch1('A');
    char *str = "hello";

    //std::tuple<数组元素类型>数组变量名(数组元素变量名);
    std::tuple<int, double, char, const char *>mytuple(int1, double1, ch1, str);//创建一个多元数组，可以存放不同类型的元素

    auto data0 = std::get<0>(mytuple);//下标只能是常量
    auto data1 = std::get<1>(mytuple);
    auto data2 = std::get<2>(mytuple);
    auto data3 = std::get<3>(mytuple);

    std::cout << typeid(data0).name() << " " << data0 << std::endl;//在C++中，typeid用于返回指针或引用所指对象的实际类型。
    std::cout << typeid(data1).name() << " " << data1 << std::endl;
    std::cout << typeid(data2).name() << " " << data2 << std::endl;
    std::cout << typeid(data3).name() << " " << data3 << std::endl;

    decltype(data0) dataA;//根据一个变量，创建一个备份

    system("pause");
}

map, multimap的区别：map每一个结点是映射，multimap每一个结点是映射链表的开头

1 map

2 multimap

1 map

映射(map) 由{键，值}对组成的集合，以某种作用于键对上的谓词排列 <map>

如果已经有重复的元素，将会插入失败

#include <iostream>
#include <map>

int main()
{
    std::map<const char *, int>mymap;

    mymap.insert(std::pair<const char *, int>("司令1", 101));
    mymap.insert(std::pair<const char *, int>("司令2", 102));
    mymap.insert(std::pair<const char *, int>("司令3", 103));
    mymap.insert(std::pair<const char *, int>("司令4", 104));

    mymap.insert(std::pair<const char *, int>("司令1", 105));//如果已经有重复的元素，将会插入失败

    auto ib = mymap.begin();
    auto ie = mymap.end();

    for (; ib != ie; ib++)
    {
        std::cout << ib->first << " " << ib->second << std::endl;
    }
    
    return 0;
}

映射

#include <iostream>
#include <map>

struct student
{
    char *name;
    int year;
};

struct stuinfo
{
    int id;
    student stu;
};

int main()
{
    stuinfo infoarray[] = { {10,{"hello",21}},{ 5,{ "hello",20 }},{25,{ "hello",30 }} };

    std::map<int, student>m;

    for (int i = 0; i < 3; i++)
    {
        m[infoarray[i].id] = infoarray[i].stu;
    }

    auto ib = m.begin();
    auto ie = m.end();

    for (; ib != ie; ib++)//遍历
    {
        std::cout << (*ib).first << " ";
        std::cout << (*ib).second.name << " " << (*ib).second.year << std::endl;
    }

    return 0;
}

2 multimap

#include <iostream>
#include <map>

int main()
{
    std::multimap<const char *, int>mymap;

    mymap.insert(std::pair<const char *, int>("司令1", 101));
    mymap.insert(std::pair<const char *, int>("司令2", 102));
    mymap.insert(std::pair<const char *, int>("司令3", 103));
    mymap.insert(std::pair<const char *, int>("司令4", 104));

    mymap.insert(std::pair<const char *, int>("司令1", 105));//multimap如果有重复，也会插入成功

    auto ib = mymap.begin();
    auto ie = mymap.end();

    for (; ib != ie; ib++)
    {
        std::cout << ib->first << " " << ib->second << std::endl;
    }
    
    return 0;
}

multimap的元素可以重复，因此equal_range(const T&);可以实现查找多个相同的元素

#include <iostream>
#include <map>
#include <string>

void main()
{
    std::multimap<std::string, std::string>mymap;

    mymap.insert(std::pair<std::string, std::string>("hello", "a"));
    mymap.insert(std::pair<std::string, std::string>("world", "b"));
    mymap.insert(std::pair<std::string, std::string>("hello", "c"));
    mymap.insert(std::pair<std::string, std::string>("world", "d"));

    auto ib = mymap.begin();
    auto ie = mymap.end();

    for (; ib != ie; ib++)
    {
        std::cout << ib->first << " " << ib->second << std::endl;
    }
    std::cout << std::endl;

    auto pfind = mymap.find("hello");//查找
    std::cout << pfind->first << " " << pfind->second << std::endl << std::endl;//只输出查找的第一个元素

    auto it = mymap.equal_range("hello");
    for (auto i = it.first; i != it.second; i++)
    {
        std::cout << i->first << " " << i->second << std::endl;
    }
}