Demodulation of 4-QAM
It is not completely clear what is the question but based on the last quoted paragraph, if you need to know how the 4-QAM mapping was done at transmitter. For example, if the mapping is 

bits {00} -> 0

bits {01} -> 1

bits {10} -> 2

bits {11} -> 3

then if you receive an integer stream $\{2,3,0,1,2,1\}$, then the bits are $\{10,11,00,01,10,01\}$. Does that answer? If not, what exactly is your input array?