Create a vector that gives the information about the locations of each element

I have the vector A: A=[1 3 7], and I want to create another array, say B, that contains the locations of the elements of A. That is, B=[1 0 1 0 0 0 1] Thanks

[Ismaeel]

A=[1 3 7];
v=zeros(1,max(A));
% for i=1:length(A)
v(A(:))=1
% end

Answer 1

[KSSV]

   A=[1 3 7] ;
   B = zeros(1,max(A)) ;
   B(A) = 1

Or Straight away

B(A) = 1