c++ STL关联式容器的共性(权哥)

/*关联式容器共性：都是用二叉查找树实现的，都自动根据关键字排序set<K>,  multiset<K>, map<K,V>, multimap<K,V)查找：.find(key)返回一个迭代器指向找到的第一个元素，失败返回.end()统计：.count(key)统计关键字等于key的元素的个数删除：.erase(key)删除关键字等于key的所有元素区间：.lower_bound(key)取得关键字为key的第一个元素的位置, .upper_bound(key)取得关键字为key的最后一个元素之后的位置， .equal_range(key)一次取得关键字为key的元素的区间，返回一个pair插入：.insert(element)构造函数：可以用比较函数作为参数bool(*compare)(K a,K b)*/#include <set>#include <iostream>using namespace std;#include "../stl2/print.h"struct Person{string name;int age;public:Person(const char* n, int a):name(n),age(a){}};bool operator<(const Person& a, const Person& b){return a.age<b.age||a.age==b.age&&a.name<b.name;}ostream& operator<<(ostream&o, const Person& x){return o<<x.name<<':'<<x.age;} int main(){multiset<Person> mp;mp.insert(Person("ZYP",26));mp.insert(Person("GYR",18));mp.insert(Person("YLB",20));mp.insert(Person("ZYP",26));mp.insert(Person("ZYP",26));mp.insert(Person("WCB",21));mp.insert(Person("GYR",18));mp.insert(Person("YLB",20));mp.insert(Person("ZHM",22));mp.insert(Person("ZYP",26));mp.insert(Person("GYR",18));mp.insert(Person("WCB",21));mp.insert(Person("GYR",18));mp.insert(Person("WCB",21));mp.insert(Person("GYR",18));print(mp.begin(), mp.end());multiset<Person>::iterator it=mp.find(Person("ZHM",22));if(it==mp.end()) cout << "没有找到ZHM" << endl;else cout << "发现目标:" << *it << endl;it=mp.find(Person("FR",22));if(it==mp.end()) cout << "没有找到FR" << endl;else cout << "发现目标:" << *it << endl;it = mp.find(Person("GYR",18));cout << mp.count(*it) << "个" << *it << endl;it = mp.find(Person("ZYP",26));cout << mp.count(*it) << "个" << *it << endl;multiset<Person>::iterator ib, ie;ib = mp.lower_bound(Person("WCB",21));ie = mp.upper_bound(Person("WCB",21));cout << "===================" << endl;print(ib, ie);cout << "===================" << endl;pair<multiset<Person>::iterator,multiset<Person>::iterator>p=mp.equal_range(Person("YLB",20));print(p.first,p.second);typedef multiset<Person>::iterator Iter;pair<Iter,Iter>q=mp.equal_range(Person("GYR",18));print(q.first,q.second);cout << "===================" << endl;mp.erase(Person("GYR",18));mp.erase(Person("ZYP",26));print(mp.begin(), mp.end());}/*运行结果：GYR:18 GYR:18 GYR:18 GYR:18 GYR:18 YLB:20 YLB:20 WCB:21 WCB:21 WCB:21 ZHM:22 ZYP:26 ZYP:26 ZYP:26 ZYP:26 发现目标:ZHM:22没有找到FR5个GYR:184个ZYP:26===================WCB:21 WCB:21 WCB:21 ===================YLB:20 YLB:20 GYR:18 GYR:18 GYR:18 GYR:18 GYR:18 ===================YLB:20 YLB:20 WCB:21 WCB:21 WCB:21 ZHM:22 */