# deque rbegin() function in C++ STL

• Difficulty Level : Basic
• Last Updated : 16 Jun, 2022

The deque::rbegin() is an inbuilt function in C++ STL which returns a reverse iterator which points to the last element of the deque (i.e., its reverse beginning). Syntax:

`deque_name.rbegin()`

Parameter: This function does not accept any parameters. Return value: It returns a reverse iterator which points to the last element of the deque. Below programs illustrates the above function: Program 1:

## CPP

 `// C++ program to illustrate the``// deque::rbegin() function``#include ``using` `namespace` `std;` `int` `main()``{``    ``deque<``int``> dq = { 10, 20, 30, 40, 50 };` `    ``cout << ``"The deque in reverse order: "``;` `    ``// prints the elements in reverse order``    ``for` `(``auto` `it = dq.rbegin(); it != dq.rend(); ++it)``        ``cout << *it << ``" "``;` `    ``return` `0;``}`

Output:

`The deque in reverse order: 50 40 30 20 10`

Time Complexity: O(n)

Auxiliary Space: O(n)

Program 2:

## CPP

 `// C++ program to illustrate the``// deque::rbegin() function``#include ``using` `namespace` `std;` `int` `main()``{``    ``deque<``char``> dq = { ``'a'``, ``'b'``, ``'c'``, ``'d'``, ``'e'` `};` `    ``cout << ``"The deque in reverse order: "``;` `    ``// prints the elements in reverse order``    ``for` `(``auto` `it = dq.rbegin(); it != dq.rend(); ++it)``        ``cout << *it << ``" "``;` `    ``return` `0;``}`

Output:

`The deque in reverse order: e d c b a`

Time Complexity: O(n)

Auxiliary Space: O(n)

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