Understanding deque

Understanding `deque` in C++

What is `deque`?

deque (double-ended queue) is a sequence container in the C++ Standard Library that allows efficient insertion and deletion of elements at both the front and the back. It provides similar functionalities to vector but with the added flexibility of efficiently managing elements at both ends.

Why Use `deque`?

Bidirectional Access: Allows insertion and deletion at both the front and back.
Dynamic Size: Can grow and shrink dynamically.
Random Access: Provides random access to elements, similar to vector.

Syntax

Here's the basic syntax for creating a deque:

#include <deque>
using namespace std;

deque<ElementType> dequeName;

ElementType: The type of elements stored in the deque.
dequeName: The name of the deque object.

Common `deque` Functions

`push_back`

Description: Adds an element to the end of the deque.

Syntax:

void push_back(const value_type& value);

Example:

#include <iostream>
#include <deque>
using namespace std;

int main() {
    deque<int> myDeque;
    myDeque.push_back(10);
    myDeque.push_back(20);
    myDeque.push_back(30);

    for (const int& val : myDeque) {
        cout << val << " ";
    }
    cout << endl;

    return 0;
}

`push_front`

Description: Adds an element to the front of the deque.

Syntax:

Example:

`pop_back`

Description: Removes the last element from the deque.

Syntax:

Example:

`pop_front`

Description: Removes the first element from the deque.

Syntax:

Example:

`front`

Description: Accesses the first element of the deque.

Syntax:

Example:

`back`

Description: Accesses the last element of the deque.

Syntax:

Example:

`empty`

Description: Checks if the deque is empty.

Syntax:

Example:

`size`

Description: Returns the number of elements in the deque.

Syntax:

Example:

Understanding deque