Removing elements and putting them in a different array

Hi everyone, My question is, how can I transform this k=[x1 x2 x3 x4 x5] into this a=[x2 x3] (random values from k) y b=[x1 x4 x5] (the rest), if sum(a)<35. In this example, ive managed to obtain matriz 'a':

clc
clear all
k=[19 16 11 15 8 8 7 14 6 11];
a=k(randperm(10)); 
i=11;
while 1
    i=i-1;
    y=randi(i);
    if sum(a)<=35
        break
    else
        a(:,y)=[];
    end
end
However, when i want to get matriz 'b', it says 'Index exceeds matrix dimensions.'

clc
clear all
k=[19 16 11 15 8 8 7 14 6 11];
a=k(randperm(10)); 
i=11;
b=[];
while 1
    i=i-1;
    y=randi(i);
    if sum(a)<=35
        break
    else
        a(:,y)=[]; 
        b=[b a(:,y)];
    end
end

Thank you in advance for any advice you can offer.

[Adam]

doc setdiff

will give you b without the need of loops.

[gonzalo salazar]

Thanks, but this command is not considering repeated values.

Answer 1

[Guillaume]

I would recommend that you use better variable names. Ones that have meaning.

The simplest way to solve your problem is to work with the indices of k instead of the values themselves.

k = [19 16 11 15 8 8 7 14 6 11];
indicestokeep = randperm(numel(k));
while true
   if sum(k(indicestokeep)) <= 35
     break;
   else
     indicestokeep = indicestokeep(1:end-1);  %always remove the last one since order is random
   end
end
a = k(indicestokeep)
b = k(setdiff(1:numel(k), indicestokeep))

[gonzalo salazar]

Wow¡¡¡¡¡¡, it is much more than I expected. Thank you very much.