In programming, there are many cases where we need to swap two elements in an array or a container like a vector. Swapping elements is a common operation that allows us to rearrange the order of elements in a collection.

In this blog post, we will explore how to swap elements in a vector using different approaches in C++. Let’s get started!

Approach 1: Using std::swap

The simplest way to swap elements in a vector is by using the std::swap function provided by the C++ Standard Library. This function takes two references as arguments and swaps their values.

std::vector<int> vec {1, 2, 3, 4, 5};

std::swap(vec[1], vec[3]);

// Output: [1, 4, 3, 2, 5]

In the example above, we have a vector vec and we want to swap the elements at indices 1 and 3. By calling std::swap(vec[1], vec[3]), the values at indices 1 and 3 are swapped, resulting in the updated vector [1, 4, 3, 2, 5].

Approach 2: Using std::iter_swap

Another approach to swapping elements in a vector is by utilizing the std::iter_swap function. This function swaps the values of two iterators.

std::vector<int> vec {1, 2, 3, 4, 5};

auto it1 = vec.begin() + 1;
auto it2 = vec.begin() + 3;

std::iter_swap(it1, it2);

// Output: [1, 4, 3, 2, 5]

In the above example, we obtain the iterators it1 and it2 pointing to the elements we want to swap, which are at indices 1 and 3. By calling std::iter_swap(it1, it2), the values at these iterators get swapped, resulting in the updated vector [1, 4, 3, 2, 5].

Conclusion

Swapping elements in a vector is a common operation that can be achieved using different approaches in C++. Whether you choose to use std::swap or std::iter_swap, both options provide simple and efficient ways to rearrange the order of elements in a vector.

By mastering these swapping techniques, you’ll have more flexibility and control over the contents of your vectors, opening up a wide range of possibilities for manipulating and organizing data.

#programming #cpp