0100 Output: 0x43 # binary 0100 0011 Explanation: low nibble 0x4 and high nibble 0x3 are swapped.

Solution

Method 1 — Mask and shift (clear and combine)

Intuition

The byte consists of a high nibble (bits 4..7) and a low nibble (bits 0..3). Extract each nibble using masks, shift them to the opposite position and combine with bitwise OR.

Approach

Compute low = x & 0x0F and high = x & 0xF0.
Shift low left by 4 and high right by 4.
Combine: result = (low << 4) | (high >> 4) and mask with 0xFF if desired.
Return

Related Tags

Continue Practicing