Using randperm to generate a shuffled cell array. How do i get the original ordered cell array

I try to create a trivia-game where the user have to enter F for a false question and T for a true question.

I have a cell array Q containing several strings of questions. To sort Q randomly, I do this:

neworder = randperm(numel(Q));
Qshuffled = Q(neworder)

Using a while-loop I create a cell array R containing -1 for wrong answers given by the user, 0 if no answers is given and 1 for correct answers. Now (naturally) the order of answers in R corresponds to the order of questions in Qshuffled. I now want to re-order R to the same order as Q, so that the answers given by the user can be compared to the original order of questions in Q.

I hope someone can help me. Thanks.

If it helps the While-loop looks like this (A is a logical vector containing 1 for true answer and 0 for false answer)

neworder = randperm(numel(Q));
Qshuffled = Q(neworder);
A = A(neworder);
while  run_random == 1 && i <= numofQ
    tic
    userinput = input([Qshuffled{i} ' '], 's');
    switch userinput
        case 'T'
            if isequal(1, A(i))
                R(i) = 1;
            else
                R(i) = -1;
            end
        case 'F'
            if isequal(0, A(i))
                R(i) = 1;
            else
                R(i) = -1;
            end
        case ''
            R(i) = 0;
        case 'Afslut'
            break
        otherwise
            display(' ')
            display('Dit input er ugyldigt.')
            display (' ')
            pause(1.5)
            display('Tast:')
            display('       ''T'' for sandt udsagn.')
            display('       ''F'' for falsk udsagn.')
            display('       ''Enter-knappen'', hvis du ikke kender svaret.')
            display('       ''Afslut'' hvis du ønsker at forlade testen.')
            display(' ')
            Askagain = 1;
    end
    O{i} = Qshuffled{i};
    T(i) = toc;
    if Askagain == 0
        i = i + 1;
    else
        Askagain = 0;
    end
end

Answer 1

[Azzi Abdelmalek]

Example

a={'a' 'b' 'c' 'd' 'e' 'f'}
n=numel(a)
ii=randperm(n)
[~,previous_order]=sort(ii)
b=a(ii)

%to get a

old_a=b(previous_order)

[Kenneth]

Thank you so much Azzi!

Im quite new to matlab, so this might be a stupid question. But will you please explain what the ~ does?

[Azzi Abdelmalek]

For example

[a,b]=sort([3 2 5])
% a is a sorted array
% b is the corresponding inf=dices

If you don't need a, just write

[~,b]=sort([3 2 5])

[Kenneth]

oh, i see.

Again, thanks a lot