Replacing alternate columns of matrix with another matrix

I have a matrix A and B, i need to replace alternate rows of B with A to form C

A={

1

2

3

}

B= {

4 7 10

5 8 11

6 9 12

}

C= {

1 4 1 7 1 10

2 5 2 8 2 11

3 6 3 9 3 12

}

Please let me know how to do this

Answer 1

[the cyclist]

Here is one way:

[m,n] = size(B);

C = zeros(m,2*n);

C(:,1:2:end) = repmat(A,[1,n]);
C(:,2:2:end) = B;

Answer 2

[David Sanchez]

A= [1;2;3];
B = [4 7 10;
    5 8 11;
    6 9 12];

C = zeros(size(B,2),size(B,1)*2); % initialize C

for k=1:length(A)
    C(:,2*k-1) = A;
    C(:,2*k) = B(:,k);
end