How to compare two matrices of different dimensions?

I have a matrix B of dimension bx2 and a matrix A of dimension ax5 with the following characteristics:

B=[1 18; 1 19; 3 1; 4 18; 4 20; 5 18; 6 12] %In the first column of B elements are always in ascending order but can be repeated more than once
A=[1 18 19 19 20; 2 7 8 9 10; 3 1 2 2 3; 4 18 19 19 20; 5 18 19 19 20; 6 11 12 13 14] %In the first column of A elements are always in ascending order, they start from 1 and end at a=6 and they are at a distance of 1

I want to construct a matrix C of dimension ax5

 C=[1 1 1 0 0; 2 0 0 0 0; 3 1 0 0 0; 4 1 0 0 1; 5 1 0 0 0; 6 0 1 0 0]

Basically in C I do the following: I take A(i,1) and pick the rows j of A with B(j,1) equal to A(i,1); for these rows I pick B(j,2) and reports C(i,h)=1 is B(j,2)=A(i,h).

Answer 1

[Andrei Bobrov]

 B=[1 18; 1 19; 3 1; 4 18; 4 20; 5 18; 6 12];
 A=[1 18 19 19 20; 2 7 8 9 10; 3 1 2 2 3; 4 18 19 19 20; 5 18 19 19 20; 6 11 12 13 14];

 x = accumarray(B(:,1),B(:,2),[max(B(:,1)),1],@(x){x});
 C = [A(:,1),cell2mat(arrayfun(@(z)ismember(A(z,2:end),x{z}),A(:,1),'un',0))];

add

A = [5   18   19   19   20
    2    7    8    9   10
    6   11   12   13   14
    1   18   19   19   20
    4   18   19   19   20
    8   30   21    0   15];

B=[1 18; 1 19; 3 1; 4 18; 4 20; 5 18; 6 12];

x = accumarray(B(:,1),B(:,2),[max(B(:,1)),1],@(x){x});
C = zeros(size(A));
C(:,1) = A(:,1);
[l,ii] = ismember(A(:,1),(1:numel(x))');
ix = find(l);
ia = ii(l);
C(l,2:end) = cell2mat(arrayfun(@(y,z)ismember(A(y,2:end),x{z}),ix,ia,'un',0));

[MRC]

I have just realized that if the last/first element of B(:,1) is different from the last/first element of A(:,1) (6 in this case), the code does not work. Could you fix it? Thanks

[Andrei Bobrov]

Hi Cris! Please see code in this answer after word add.

Answer 2

[Georgia Petsios]

this solution doesnt work with double matrices..