92. Compress Interleaved Bits Reverse Bit Spreading

In the previous problem, we interleaved an 8-bit number into a 16-bit value by inserting 0s between each bit. Now your task is to:

• Reverse the interleaving process
• Extract only the bits from even-numbered positions in a 16-bit number
• Reconstruct the original 8-bit value
   

Example Logic

16-bit input:

[b15 b14 ... b1 b0]

Extract bits at positions: 0, 2, 4, 6, 8, 10, 12, 14 → and shift into:

b0 b1 b2 b3 b4 b5 b6 b7

Example-1

Input: val = 20548 → Binary: 0101000001000100
Output: 202 (Binary: 11001010)

Example-2

Input: val = 21845 → Binary: 0101010101010101
Output: 255 (Binary: 11111111)

Example-3

Input: val = 1 → Binary: 0000000000000001
Output: 1