MATLAB: Compare 2 vectors and classify them

Question

I have an array of 90872×2 double. As follows:

A= B=

1 2

1 2

1 2

1 1

1 1

1 1

1 1

2 1

2 1

2 1

2 1

1 2

1 2

1 2

1 2

1 1

1 1

1 1

2 2

2 2

I want to create a column C with the following values accordinf to the following conditions:

1= when A==1 and B==1;

2= when A==1 and B==2;

3= when A==2 and B==1;

4= when A==2 and B==2;

Therefore I will have:

A= B= C=

1 2 2

1 2 2

1 2 2

1 1 1

1 1 1

1 1 1

1 1 1

2 1 3

2 1 3

2 1 3

2 1 3

1 2 2

1 2 2

1 2 2

1 2 2

1 1 1

1 1 1

1 1 1

2 2 4

2 2 4

any help?

Answer 1

C = 1 * (A==1 & B==1) + 2 * (A==1 & B==2) +...
    3 * (A==2 & B==1) + 4 * (A==2 & B==2)