5.set和multiset的区别

#include<iostream>
using namespace std;

#include<set>

void test0501()
{
    set<int> s1;
    
    pair<set<int>::iterator,bool> ret=s1.insert(10);//对组表示返回两个值，返回插入位置的迭代器(iterator)和是否插入成功(bool)

    if (ret.second)//第二个返回值bool表示是否插入成功
    {
        cout << "插入成功" << endl;
    }
    else
    {
        cout << "插入失败" << endl;
    }

    ret= s1.insert(10);//不允许重复，故失败
    if (ret.second)
    {
        cout << "插入成功" << endl;
    }
    else
    {
        cout << "插入失败" << endl;
    }

    multiset<int> s2;
    
    s2.insert(12);
    s2.insert(321);
    s2.insert(10);//可以重复插入
    s2.insert(10);
    for (multiset<int>::iterator it = s2.begin(); it != s2.end(); it++)
    {
        cout << (*it) << " ";
    }
    cout << endl;
}
int main()
{

    test0501();

    system("pause");
    return 0;
}