原创 linux下c++ lesson24 容器set

1-set的使用.cpp

#include <iostream>
#include <set>

using namespace std;

class Student
{
private:	
	int id;
	string name;
public:
	Student(int i, string n);
	void show()const;
	bool operator<(const Student &s) const;
	bool operator>(const Student &s) const;
};

Student::Student(int i, string n)
{
	id = i;
	name = n;
}

void Student::show() const
{
	cout << "id " << id << "    name " << name << endl; 
}

bool Student::operator<(const Student &s) const
{
	return this->id < s.id;
}

bool Student::operator>(const Student &s) const
{
	return this->id > s.id;
}

int main()
{
	Student s1(3, "aa");
	Student s2(1, "zz");
	Student s3(5, "ff");
	Student s4(4, "ee");
	Student s5(2, "bb");
	Student s6(7, "cc");
	Student s7(8, "hh");
	Student s8(6, "jj");

	//set<Student> s;
	set<Student, greater<Student> > s;

	s.insert(s1);
	s.insert(s2);
	s.insert(s3);
	s.insert(s4);
	s.insert(s5);
	s.insert(s6);
	s.insert(s7);
	s.insert(s8);

	for (set<Student>::iterator it = s.begin(); it != s.end(); it++)
	{
		it->show();
	}

	cout << "集合大小：" << s.size() << endl;

	cout << "set的删除" << endl;
	s.erase(s.begin());
	for (set<Student>::iterator it = s.begin(); it != s.end(); it++)
	{
		it->show();
	}

	cout << "set区间删除" << endl;
	s.erase(--(s.end()), s.end());
	for (set<Student>::iterator it = s.begin(); it != s.end(); it++)
	{
		it->show();
	}
	
	cout << "set删除具体元素" << endl;
	Student stu(3, "zz");    //按照id查找并删除
	s.erase(stu);
	for (set<Student>::iterator it = s.begin(); it != s.end(); it++)
	{
		it->show();
	}

	cout << "set的查找" << endl;
	//set<Student, greater<Student> >::iterator it = s.find(stu);
	set<Student, greater<Student> >::iterator it = s.find(s6);
	if (it == s.end())
	{
		cout << "对象不存在" << endl;
	}
	else
	{
		it->show();
	}

	cout << "set的统计" << endl;
	cout << s.count(s6) << endl;

	cout << "lower_bound" << endl;
	Student ss(3, "aaa");
	it = s.lower_bound(ss);
	if (it == s.end())
	{
		cout << "不存在" << endl;
	}
	else
	{
		it->show();
	}

	cout << "upper_bound" << endl;
	it = s.upper_bound(s6);
	if (it == s.end())
	{
		cout << "不存在" << endl;
	}
	else
	{
		it->show();
	}

	cout << "equal_range" << endl;
	//pair 类型 模板类 有两个成员变量
	pair<set<Student, greater<Student> >::iterator, set<Student, greater<Student> >::iterator> p;    //创建pair对象
	p = s.equal_range(ss);
	p.first->show();      //p.first第一个类型（迭代器）
	p.second->show();     //p.second第二个类型（迭代器）

	return 0;
}