Copy a vector to another vector in reverse order

Question

I am new in C++.
I need to copy a vector in reverse order to another vector.

Here's how i did it :

int temp[] = {3, 12, 17};

vector<int>v(temp, temp+3);

vector<int>n_v;

n_v=v;
reverse(n_v.begin(), n_v.end()); //Reversing new vector

Is there any simple way to copy a vector in reverse order to another vector in STL?

[This answer](http://stackoverflow.com/questions/11019722/how-to-reverse-a-vector-of-strings-in-c/11019765#11019765) covers most variations on this theme, (Found by searching this site for "[c++] copy a vector in reverse order".) — molbdnilo, Jan 26 '15 at 10:22

score 21 · Accepted Answer · answered Jan 26 '15 at 10:19

21

Simply just do this:

vector<int>n_v (v.rbegin(), v.rend());

answered Jan 26 '15 at 10:19

Ali Akber

score 2 · Answer 2 · answered Jan 26 '15 at 10:20

2

You may use reverse_iterator:

std::vector<int> n_v(v.rbegin(), v.rend());

answered Jan 26 '15 at 10:20

Jarod42

score 0 · Answer 3 · answered Jul 11 '22 at 22:41

From C++20, the views can be used.

std::vector v = { 1,2,3,4,5,6,7,8 };
auto result = v | std::views::reverse ;

Here the result can be directly iterated 8 7 6 5 4 3 2 1.

But if still need a vector

std::vector rev_v(std::ranges::begin(result), std::ranges::end(result));

The advantage of these viewer adapters is, we can chain up multiple requirements.

For example, if the requirement says, reverse the vector, get the first four squaring them. We can do this in one statement.

auto result = v | std::views::reverse | std::views::take(4) | std::views::transform([](int i) { return i * i; });

The output is 64 49 36 25

3 Answers3