How to Create a Stack of Deque 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 whereas a deque (double-ended queue) are sequence container with the feature of expansion and contraction on both ends. In this article, we will learn how to create a stack of deque in C++.

Example:

Input: 
myDeque1 = 1, 2, 3, 4
myDeque2 = 5, 6, 7
Output: 
Stack of Deque: [ {5, 6, 7},
 {1, 2, 3, 4} ]

Stack of Deque in C++

To create a stack of deques in C++, we need to pass the std::deque as the template parameter in the declaration of the stack. We can then use the std::stack::push() function to insert the deque container in the stack.

Syntax to Create a Stack of Deque in C++

stack<deque<datatype>> stack_name; 

Here,

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

C++ Program to Use a Stack with a Deque

The below program demonstrates how we can create a stack of deque in C++.

Elements in the Stack of Deque:
7 6 5 4 3 2 1 

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