How to Traverse a List with reverse_iterator in C++?

In C++, lists are containers that allow users to store data in non-contiguous memory locations. List provides reverse iterators that make it easy to traverse the list in reverse order. In this article, we will learn how to traverse a list with reverse_iterator in C++.

Example

Input:
myList = {10,20,30,40,50}

Output:
50 40 30 20 10

Iteratore a List with reverse_iterator in C++

Reverse iterators in C++ are used to traverse the list in a backward direction starting from the end of the list towards the beginning. The std::list class template has two member functions that provide the reverse iterators:

• list::rbegin(): Returns the reverse iterator pointing to the last element in the list.
• list::rend(): Returns a reverse iterator pointing to the element just before the first element in the list.

C++ Program to Traverse a List with reverse_iterator

The following program illustrates how we can traverse a list using a reverse_iterator in C++:

// C++ Program to illustrate how to traverse a list with
// reverse_iterator
#include <iostream>
#include <list>
using namespace std;

int main()
{
    // Initializing  a List
    list<int> l = { 10, 20, 30, 40, 50 };
    // Declare the reverse iterator of the list
    list<int>::reverse_iterator it;

    // Traverse the  elements of the list using  the
    // reverse_iterator
    for (it = l.rbegin(); it != l.rend(); it++) {
        cout << *it << " ";
    }
  
    return 0;
}

50 40 30 20 10 

Time Complexity: O(N) where N is the size of the list.
Auxiliary Space: O(1)