forward_list::reverse() in C++ STL

std::forward_list::reverse() is an inbuilt function in CPP STL which reverses the order of the elements present in the forward_list.

Syntax:

forwardlist_name.reverse()

Parameter: The function does not accept any parameter.

Return value: The function has no return value. It reverses the forward list.

Below program demonstrates the above function:

Program 1:

CPP

// C++ program to illustrate the
// reverse() function
#include <bits/stdc++.h>
using namespace std;

int main()
{
    // initialising forward list
    forward_list<int> forward = { 10, 20, 40, 30, 70 };

    cout << "List elements before performing reverse operation: ";

    for (auto it = forward.begin(); it != forward.end(); ++it)
        cout << *it << " ";

    // Function that performs reverse operation
    forward.reverse();

    // printing elements of list
    cout << "\nList elements after performing reverse operation: ";

    for (auto it = forward.begin(); it != forward.end(); ++it)
        cout << *it << " ";

    return 0;
}

Output

List elements before performing reverse operation: 10 20 40 30 70 
List elements after performing reverse operation: 70 30 40 20 10

 Time Complexity: O(n)

Auxiliary Space: O(n)