代码:
附上map类标准库资料:https://en.wikipedia.org/wiki/Associative_containers
#include<string>
#include<iostream>
#include<map>
using namespace std;
/*map中的数据是默认按照key值自动排序的,如果需要修改排序规则,可以运算符重载<*/
struct person
{
string name;
int age;
person(string name, int age)
{
this->name = name;
this->age = age;
}
bool operator < (const person& p) const//运算符左侧对象为调用对象,右侧对象为传参对象
{
return this->name < p.name;
}
};
map<person, int> m;
int main()
{
person p1("Tom1", 20);
person p2("Tom2", 22);
person p3("Tom3", 22);
person p4("Tom4", 23);
person p5("Tom5", 24);
m.insert(make_pair(p3, 100));
m.insert(make_pair(p4, 100));
m.insert(make_pair(p5, 100));
m.insert(make_pair(p1, 100));
m.insert(make_pair(p2, 100));
cout << "地图中的原始数据:" << endl;
for (map<person, int>::iterator iter = m.begin(); iter != m.end(); iter++)
{
cout << iter->first.name << "\t" << iter->first.age << "\t" << iter->second << endl;
}
cout << m.size() << "\t" << m.max_size() << endl;
cout << "erase操作后的地图数据:" << endl;
map<person, int>::iterator iter = m.end();//就像数组begin取得是0,end取的是n,超过索引值
m.erase(--iter);
for (map<person, int>::iterator iter = m.begin(); iter != m.end(); iter++)
{
cout << iter->first.name << "\t" << iter->first.age << "\t" << iter->second << endl;
}
cout << m.size() << "\t" << m.max_size() << endl;
cout << "clear操作后的地图数据:" << endl;
m.clear();//清除地图
for (map<person, int>::iterator iter = m.begin(); iter != m.end(); iter++)
{
cout << iter->first.name << "\t" << iter->first.age << "\t" << iter->second << endl;
}
cout << m.size() << "\t" << m.max_size() << endl;
system("pause");
return 0;
}