I fail to see the problem, although you are the only one who knows the rules that created this vector, so you will know what to search for.
You just use a while loop.
- Whatever the first element is, (here, it is a 1.) Locate the first element that is not a 1. That will be the number 2.
- Now, locate the first element that is not a 1 or 2. Then permute everything between elements 1 and the element that precedes the 4.
Iterate the above steps until the vector is fully permuted.
However, there will be no simply vectorized solution that will magically do what you want. It is just a question of writing the brute force code. As I said, a sequence of finds inside a while loop. Once you find the bounds on the current set of elements, then you do a permutation.
