STL

 

 

 

 

 

 

#include<set>
#include<iostream>

using namespace std;

void printf(set<int>& s)
{
    if (s.empty())
    {
        cout << "这玩意是空的" << endl;
    }
    else
    {
        for (auto& a:s)
        {
            cout << a << " ";
        }
        cout << endl;
    }
    
}

//插入与查找 。不能随机访问，插入后，自动排序,从小到大
void test01()
{
    set<int> s1;
    s1.insert(19);
    s1.insert(20);
    s1.insert(14);
    s1.insert(2);
    s1.insert(8);
    printf(s1);
    //find
    set<int>::iterator itr1 = s1.find(14);
    if (itr1 == s1.end())     cout << "can not be found !" << endl;
    else                      cout << " be found !" << endl;
    //lower_bound
    set<int>::iterator itr2 = s1.lower_bound(8);// 返回 >=8 的迭代器
    if (itr2 == s1.end())     cout << "can not be found !" << endl;
    else                      cout << "lower_bound = " << *itr2 << endl;
    //upper_bound
    set<int>::iterator itr3 = s1.upper_bound(8);// 返回 > 8 的迭代器
    if (itr3 == s1.end())     cout << "can not be found !" << endl;
    else                      cout << "upper_bound = " << *itr3 << endl;
    //equal_range = lower_bound + upper_bound
    typedef set<int>::iterator setItr;
    pair<setItr, setItr> itr4 = s1.equal_range(8);
    if (itr4.first == s1.end())     cout << "can not be found !" << endl;
    else                            cout << "equal_range first = " << *itr4.first << endl;
    if (itr4.second == s1.end())    cout << "can not be found !" << endl;
    else                            cout << "equal_range second = " << *itr4.second << endl;
}

void test02()
{
    //<1>
    pair<string, int> key_value1("shiruiyu", 10);
    pair<string, int> key_value2 = make_pair("maozedong", 99);
    //<2>
}

//仿函数,起始是一个类
class MyCampcare
{
public:
    bool operator()(int a, int b)
    {
        return a > b;
    }
};

void test03()
{
    set<int, MyCampcare> set1;
    set1.insert(22);
    set1.insert(1);
    set1.insert(10);
    set1.insert(12);
    //从大到小 打印
    for (auto& set_:set1)
    {
        cout << set_ << " ";
    }
    cout << endl;
}

class Person
{
public:
    Person(int age, int id) :age_(age), id_(id) {};
    ~Person() {};
    int age_;
    int id_;
};

//仿函数
class MyCampare_
{
public:
    bool operator()(Person p1, Person p2)
    {
        return p1.id_ > p2.id_;
    }
};

void test04()
{
    set<Person, MyCampare_> set1;// 按照id_ 从大到小排序    
    Person p1(20, 1), p2(21, 4), p3(23, 2), p4(22, 3);
    set1.insert(p1);
    set1.insert(p2);
    set1.insert(p3);
    set1.insert(p4);
}

int main()
{
    test01();
    test02();
    test03();
    test04();
    return 1;
}