How can i encode and decode two number in a single integer using bit manipulations?

Question

I was learning about bit manipulations then I thought of this. Say I have two numbers, First in the range of [1,6] and second in the range of [0,3]. Now the first number can take max 3 bits to be stored and the second can take 2 bits to be stored. How can I use one int32 to store both of them in it. Thanks.

Answer 1

Encode:

// a : range of [1,6], bit0 ~ bit2
// b : range of [0,3], bit3 ~ bit4
// c : encoded int32
c = 0;
c |= (a | b << 3);

Decode:

a = (c & 0x00000007);
b = (c & 0x00000018) >> 3;