C++之set/multise容器
set基本概念
set构造和赋值
#include <iostream>
#include<set>
using namespace std;
void PrintfSet(set<int>&s)
{
for(set<int>::iterator it = s.begin();it != s.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
void test()
{
set<int> s1;
//插入数据，只有insert方式
s1.insert(10);
s1.insert(40);
s1.insert(20);
s1.insert(40);
s1.insert(30);
//set容器特点: 所有元素插入时候自动被排序
//set容器不允许插入重复值
PrintfSet(s1);
//拷贝构造
set<int>s2(s1);
PrintfSet(s2);
//赋值操作
set<int>s3;
s3 = s1;
PrintfSet(s3);
}
int main()
{
test();
cout << "Hello World!" << endl;
return 0;
}
set大小和交换
#include <iostream>
#include<set>
using namespace std;
void PrintfSet(set<int>&s)
{
for(set<int>::iterator it = s.begin();it != s.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
void test()
{
set<int> s1;
//插入数据，只有insert方式
s1.insert(10);
s1.insert(40);
s1.insert(20);
s1.insert(40);
s1.insert(30);
//set容器特点: 所有元素插入时候自动被排序
//set容器不允许插入重复值
PrintfSet(s1);
if(s1.empty())
{
cout<<"s1 is empty"<<endl;
}
else
{
cout<<"s1 is not empty"<<endl;
cout<<"s1's size is "<<s1.size()<<endl;
}
set<int>s2;
s2.insert(100);
s2.insert(200);
s2.insert(300);
s2.insert(400);
//swap
cout<<"before swap"<<endl;
PrintfSet(s1);
PrintfSet(s2);
s2.swap(s1);
cout<<"after swap"<<endl;
PrintfSet(s1);
PrintfSet(s2);
}
int main()
{
test();
cout << "Hello World!" << endl;
return 0;
}
set插入和删除
#include <iostream>
#include<set>
using namespace std;
void PrintfSet(set<int>&s)
{
for(set<int>::iterator it = s.begin();it != s.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
void test()
{
set<int> s1;
//插入数据，只有insert方式
s1.insert(10);
s1.insert(40);
s1.insert(20);
s1.insert(40);
s1.insert(30);
//set容器特点: 所有元素插入时候自动被排序
//set容器不允许插入重复值
PrintfSet(s1);
s1.erase(s1.begin());
PrintfSet(s1);
s1.erase(30);
PrintfSet(s1);
//s1.erase(s1.begin(),s1.end());
s1.clear();
}
int main()
{
test();
cout << "Hello World!" << endl;
return 0;
}
set查找和统计
#include <iostream>
#include<set>
using namespace std;
void PrintfSet(set<int>&s)
{
for(set<int>::iterator it = s.begin();it != s.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
void test()
{
set<int> s1;
//插入数据，只有insert方式
s1.insert(10);
s1.insert(40);
s1.insert(20);
s1.insert(40);
s1.insert(30);
//set容器特点: 所有元素插入时候自动被排序
//set容器不允许插入重复值
PrintfSet(s1);
set<int>::iterator pos = s1.find(30);
if(pos != s1.end())
{
cout<<"have finded"<<endl;
}
else
{
cout<<"no find"<<endl;
}
//对于set而言 统计结果 要么是0 要么是1
int num = s1.count(30);
cout<<"num is "<<num<<endl;
}
int main()
{
test();
cout << "Hello World!" << endl;
return 0;
}
set与multise区别
#include <iostream>
#include<set>
using namespace std;
void PrintfSet(set<int>&s)
{
for(set<int>::iterator it = s.begin();it != s.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
void test()
{
set<int> s1;
//插入数据，只有insert方式
pair<set<int>::iterator,bool> ret = s1.insert(10);
if(ret.second)
{
cout<<"insert success at first"<<endl;
}
else
{
cout<<"insert fail at first"<<endl;
}
ret = s1.insert(10);
if(ret.second)
{
cout<<"insert success at second"<<endl;
}
else
{
cout<<"insert fail at second"<<endl;
}
multiset<int>m1;
//允许插入重复值
m1.insert(10);
m1.insert(10);
m1.insert(10);
m1.insert(10);
for(multiset<int>::iterator it = m1.begin();it != m1.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
int main()
{
test();
cout << "Hello World!" << endl;
return 0;
}
pair对组的创建
#include <iostream>
#include<set>
using namespace std;
void PrintfSet(set<int>&s)
{
for(set<int>::iterator it = s.begin();it != s.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
void test()
{
//第一种方式
pair<string,int>p("Tom",20);
cout<<"name is "<<p.first<<"age is "<<p.second<<endl;
//第二种方式
pair<string,int>p2 = make_pair("Jin",21);
cout<<"name is "<<p2.first<<"age is "<<p2.second<<endl;
}
int main()
{
test();
cout << "Hello World!" << endl;
return 0;
}
set排序
#include <iostream>
#include<set>
using namespace std;
void PrintfSet(set<int>&s)
{
for(set<int>::iterator it = s.begin();it != s.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
class MyCompare
{
public:
bool operator()(int v1,int v2)
{
return v1>v2;
}
};
void test()
{
set<int>s1;
s1.insert(10);
s1.insert(40);
s1.insert(30);
s1.insert(50);
s1.insert(20);
PrintfSet(s1);
//指定排序规则为从大到小
set<int,MyCompare>s2;
s2.insert(10);
s2.insert(40);
s2.insert(30);
s2.insert(50);
s2.insert(20);
for(set<int,MyCompare>::iterator it = s2.begin();it != s2.end();it++)
{
cout<<*it<<" ";
}
cout<<endl;
}
int main()
{
test();
cout << "Hello World!" << endl;
return 0;
}
set存放自定义数据
#include<iostream>
#include<string>
using namespace std;
#include<set>
//set容器排序，存放自定义数据类型
class Person
{
public:
Person(string name,int age)
{
this->m_name = name;
this->m_age = age;
}
string m_name;
int m_age;
};
class MyCompare
{
public:
bool operator()(const Person&p1, const Person& p2)
{
//按照年龄进行降序
return p1.m_age > p2.m_age;
}
};
void test()
{
//指定排序规则为从大到小
set<Person, MyCompare>s;
//创建Person对象
Person p1 ("liubei",23);
Person p2("zhangfei", 21);
Person p3("guanyu", 22);
Person p4("zhaoyun", 24);
s.insert(p1);
s.insert(p2);
s.insert(p3);
s.insert(p4);
for (set<Person, MyCompare>::iterator it = s.begin();it != s.end();it++)
{
cout << "name is " << (*it).m_name << "age is " << (*it).m_age << endl;
}
cout << endl;
}
int main()
{
test();
system("pause");
return 0;
}
