Matlab: avoid for loops to find the maximum among values with same labels

Question

I need to find the maximum among values with same labels, in matlab, and I am trying to avoid using for loops.

Specifically, I have an array L of labels and

Answer 1

helper=[L.', V.'];
helper=sortrows(helper,-2);
[~,idx,~]=unique(helper(:,1));
S=helper(idx,2);

What I do is: I join the two arrays as columns. Then I sort them regarding second column with biggest element first. Then I get the idx of the unique Values in L before I return the corresponding Values from V.

The solution from Luis Mendo is faster. But as far as I see his solution doesn't work if there is a zero,negative value or a noninteger inside L:

Luis solution: Elapsed time is 0.722189 seconds.
My solution: Elapsed time is 2.575943 seconds.

I used:

L= ceil(rand(1,500)*10);
V= ceil(rand(1,500)*250);

and ran the code 10000 times.