How to Create a Stack of Unordered_Multiset in C++?

In C++, the stack is a container in which new elements are added from one end (top) and removed from that end only. In this article, we will learn how to create a stack of unordered_multiset in C++.

Example:

Input: 
mySet1 = { “apple”, “banana”, “apple” } 
mySet2 = { “orange”, “mango”, “orange” } 

Output: 
Stack of Unordered_Multiset: [ { “orange”, “mango”, “orange” },
 { “apple”, “banana”, “apple” } ]

Stack of Unordered_Multiset in C++

To create a stack of std::unordered_multiset in C++, first declare a std::stack with std::unordered_multiset as the template argument, then use the std::stack::push() function to insert the unordered_multiset in the stack.

Syntax to Create a Stack of Unordered_Multiset in C++

stack<unordered_multiset<datatype>> stack_name;

Here,

• datatype denotes the type of data stored in the unordered_multiset.
• stack_name is the name of the stack of unordered_multiset.

C++ Program to Create a Stack of Unordered_Multiset

The below program demonstrates how we can create and use a stack of unordered_multiset in C++ STL.

Elements in the Stack of Unordered_Multiset:
orange orange mango 
apple apple banana 

Time Complexity: O(N), here N is the total number of elements in each unordered_multiset.
Auxiliary Space:O(M * N), here M is the number of unordered_multiset.