Chapter 17, Problem 10RQE

Program Plan Intro

STL container classes:

An object which holds a collection of values or other objects is termed as container.

There are two types of container class:

• sequence
• associative

Associative container:

Associative container is the process of storing the data in a non-sequential order in memory.

Example of associative container:

• set
• map
• multiset
• multimap
• unordered_map

Set:

A “set” belongs to an associative container which holds a group of unique values. STL class template can be used to implement a “set” container.

• Only unique elements should be stored in the set. It should not have the same value for two elements.
• The elements contains in the set are automatically sorted in ascending order.
• In order to use “set” class, the header file “#include<set>” should be included in the program.

Multiset:

A “multiset” is an associative container which holds the duplicate elements. STL class template can be used to implement a “multiset” container.

• The multiset can store duplicate elements. The two elements can have same values.
• The element present in a multiset cannot be modified in the container but can be inserted or deleted.
• In order to use multiset class “# include” the “<set>” header file in the program.

“count()” member function:

The “count()” member function searches the element which matches the specified element in the container and returns the number of matches.