C++,stl,set/mutiset详解

目录

1.set容器的构造和赋值

2.set的大小和交换 

3.set的插入和删除

4.set的查找和统计

5.set和mutiset区别 

 6.pair对组的创建

7.set排序 

1.set的内置类型指定排序规则

2.set的自定义数据类型指定排序 

---

1.set容器的构造和赋值

#include
using namespace std;

void print(set &s)
{
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
}

int main()
{
	set s;
	
	s.insert(7);
	s.insert(3);
	s.insert(9);
	s.insert(3);
	s.insert(6);
	
	print(s);
	
	sets1(s);
	print(s1);
	
	sets2;
	s2 = s1;
	print(s2);
	
	return 0;
}

 

2.set的大小和交换 

#include
using namespace std;

void print(set &s)
{
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
}

int main()
{
	set s;
	
	s.insert(7);
	s.insert(3);
	s.insert(9);
	s.insert(3);
	s.insert(6);
	
	print(s);
	
	cout << s.empty() << endl;
	cout << s.size() << endl;
	
	sets1;
	s1.swap(s);
	print(s1);
	
	return 0;
}

 

3.set的插入和删除

 

#include
using namespace std;

void print(set &s)
{
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
}

int main()
{
	set s;
	
	s.insert(7);
	s.insert(3);
	s.insert(9);
	s.insert(3);
	s.insert(6);
	
	print(s);
	
	s.erase(s.begin());
	//删除删的是排序后那个下标所在的位置的值
	print(s);
	
	s.erase(6);
	//也可以直接删除你想删的那个值
	print(s);
	
	s.clear();
	print(s);
	
	return 0;
}

 

4.set的查找和统计

 

#include
using namespace std;

void print(set &s)
{
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
}

int main()
{
	set s;
	
	s.insert(7);
	s.insert(3);
	s.insert(9);
	s.insert(3);
	s.insert(6);
	
	print(s);
	
	set::iterator pos = s.find(6);
	
	if(pos != s.end()) cout << "找到了" << *pos << endl;
	
	cout << s.count(9) << endl;
	
	return 0;
}

 

5.set和mutiset区别 

 

#include
using namespace std;

void print(set &s)
{
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
}

int main()
{
	set s;
	
	pair::iterator,bool> ret = s.insert(7);
	
	cout << ret.second << endl;
	
	ret = s.insert(7);
	cout << ret.second << endl;
	//说明第一次插入成功，而第二次插入失败
	//而mutiset里却可以插入重复的值
	
	return 0;
}

 

 6.pair对组的创建

#include
using namespace std;

void print(set &s)
{
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
}

int main()
{
	set s;
	
	pairp1("avent",100);
	cout << p1.first << " " << p1.second << endl;
	
	pairp2 = make_pair("misha",12);
	cout << p2.first << " " <

 

7.set排序 

1.set的内置类型指定排序规则

 

#include
using namespace std;

void print(set &s)
{
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
}

class cmp
{
public:
	bool operator()(int v1,int v2)
	{
		return v1 > v2;
	}
};

int main()
{
	set s;
	
	s.insert(10);
	s.insert(80);
	s.insert(200);
	s.insert(90);
	s.insert(180);
	
	print(s);
	
	set s1;
	
	s1.insert(10);
	s1.insert(80);
	s1.insert(200);
	s1.insert(90);
	s1.insert(180);
	
	for(set::iterator it = s1.begin(); it != s1.end(); it++)
	{
		cout << *it << " ";
	}
	cout << endl;
	
	return 0;
}

 

2.set的自定义数据类型指定排序 

 

#include
using namespace std;

class person
{
public:
	person(int a,int b)
	{
		ma = a;
		mb = b;
	}
	int ma;
	int mb;
};

class cmp
{
public:
	bool operator()(const person &p1,const person &p2)
	{
		if(p1.ma == p2.ma) return p1.mb < p2.mb;
		else return p1.ma < p2.ma;
	}
};

int main()
{
	set s;
	
	person p1(10,100);
	person p2(20,200);
	person p3(10,200);
	
	s.insert(p1);
	s.insert(p2);
	s.insert(p3);
	
	for(set::iterator it = s.begin(); it != s.end(); it++)
	{
		cout << (*it).ma << " " << (*it).mb << " " << endl;
	}
	
	return 0;
}