MATLAB: How to use all the other indices except of the ones given in an array

Question

I have a vector let's say A = [1:1:100]', vector B = [1:0.5:50.5]' and a third vector with some indices such us idx = [10 11 30 35 40 90 91 92 93 99]'. I would like set the values of A corresponding to the idx to 0 and the values of B that do not correspond to the idx to 0, somethike like: A(idx) = 0 and B(~idx) = 0.

Answer 1

A(idx) = 0;
B(setdiff(1:end,idx)) = 0;