How do random state scramblers work?

[JasonDL13]

Hi.

I have no idea were I should put this, like most of my threads.

My question is, like qqTimer, or any other good timer, how do they make random states?

Do they actually take a random state then create a scramble? Is it a specially made scramble? (I've noticed for the few 10 or so turns, right, front, left, and back are all half turns, eg, F2, not F' or F)

I'm not asking for a programming tutorial, I made a random move scrambler but I'm not sure how to make it random state.

Thanks!

 

[Jakube]

A random state scrambler works like this: create a random state of the cube, solve this state, print the inverse solution.

As you migth know, you can represent each cube state as a permutation of the numbers 1 to 8 (corners), a permutation of the numbers 1 to 12 (edges), and 2 vectors with the number 0-1 or 0-2 (edge and corner orientation). You can randomly choose on of each, you just have to be carefully about parity.

Most solver's use Kociemba's algorithm, because it quickly finds short solutions. Kociemba's algorithm works in 2 stages. In the second stage, the the solver only uses moves of the group [U,D,F2,R2,B2,L2] and therefore doesn't use any F and F' moves. Notice that you could also choose [R,L,U2,D2,B2,F2] or [F,B,U2,D2,R2,L2].

 

[JasonDL13]

A random state scrambler works like this:

Thanks!