MATLAB: How can i find positions of sorted/unique values.

Question

 p = [90 90 -45 0 0 45 45 0 -45];
 q = p;
 q(1+find(q(1:end-1)==q(2:end))) = [];
 q = [90   -45     0    45     0   -45];
 idx = [true diff(p)~=0];
 q = p(idx);

i want to find positions of q according to p from right to left. Means [2 3 5 7 8 9]

Answer 1

idx = fliplr([true, diff(fliplr(p))~=0]);
out = find(idx);