Question

I have

vector<int> my_vector;
vector<int> other_vector;

with my_vector.size() == 20 and other_vector.size() == 5.

Given int n, with 0 < n < 14, I would like to replace the subvector (my_vector[n], myvector[n+1], …, myvector[n+4]) with other_vector.

For sure with the stupid code

 for(int i=0; i<5; i++)
 {
      my_vector[n+i] = other_vector[i];
 }

I’m done, but I was wondering if is there a more efficient way to do it. Any suggestion?

(Of course the numbers 20 and 5 are just an example, in my case I have bigger size!)

Answer 1

In C++11, a friendly function std::copy_n is added, so you can use it:

 std::copy_n(other_vector.begin(), 5, &my_vector[n]);

In C++03, you could use std::copy as other answers has already mentioned.