C++菜鸟迷惑问题之一:HashTable（送分无极限！连载）

[wes109]

JAVA中有一个java.util.HashTable，功能强大，非常好用
不知道C++的标准库里面有没有类似的东西？
怎么使用？（最好附代码示例）

如果没有，怎样去构造一个？

[sean717]

sgi 的 STL 有hashmap
Description
Hash_map is a Hashed Associative Container that associates objects of type Key with objects of type Data. Hash_map is a Pair Associative Container, meaning that its value type is pair<const Key, Data>. It is also a Unique Associative Container, meaning that no two elements have keys that compare equal using EqualKey.
Looking up an element in a hash_map by its key is efficient, so hash_map is useful for "dictionaries" where the order of elements is irrelevant. If it is important for the elements to be in a particular order, however, then map is more appropriate.

Example
struct eqstr
{
bool operator()(const char* s1, const char* s2) const
{
return strcmp(s1, s2) == 0;
}
};

int main()
{
hash_map<const char*, int, hash<const char*>, eqstr> months;

months["january"] = 31;
months["february"] = 28;
months["march"] = 31;
months["april"] = 30;
months["may"] = 31;
months["june"] = 30;
months["july"] = 31;
months["august"] = 31;
months["september"] = 30;
months["october"] = 31;
months["november"] = 30;
months["december"] = 31;

cout << "september -> " << months["september"] << endl;
cout << "april -> " << months["april"] << endl;
cout << "june -> " << months["june"] << endl;
cout << "november -> " << months["november"] << endl;
}

http://www.sgi.com/tech/stl/hash_map.html