How do I merge vectors?

I have a 10X1 vector A=[1;3;7;10;12;14;15;18;20;21] and a 10X1 vector B=[3;12;15;18;20;0;0;0;0;0]. Is there a way to come up with a 10X2 vector C such that the equal elements in each vector sit at the same row in vector C? I want to retain all elements of vector A in vector C and keep only the elements from vector B that have values equal to the one elements in vector A. Ideally, My final vector C would look something like this: C=[1 0;3 3;7 0;10 0;12 12;14 0;15 15;18 18;20 20;21 0]. Any thoughts?

Answer 1

[Star Strider]

The intersect function works best here:

A=[1;3;7;10;12;14;15;18;20;21];
B=[3;12;15;18;20;0;0;0;0;0];

[m,ia,ib] = intersect(A, B, 'stable');

C = [A zeros(size(A,1),1)];
C(ia,2) = B(ib)

C =

       1     0
       3     3
       7     0
      10     0
      12    12
      14     0
      15    15
      18    18
      20    20
      21     0