Swap Odd and Even Bits

Problem

Swap every pair of adjacent bits in the binary representation of a non-negative integer n and return the result.

Mask the even-position bits with 0xAAAAAAAA and shift them right, mask the odd-position bits with 0x55555555 and shift them left, then OR the two parts. Bits are numbered from 0 at the least significant position.

Hint

The two masks select alternating bits, so shifting each part by one places them in the other slot.

Test cases

case 1

in: [2]

expected: 1

case 2

in: [3]

expected: 3

case 3

in: [0]

expected: 0

case 4

in: [5]

expected: 10

case 5

in: [10]

expected: 5

Starter codePython

def swap_odd_even_bits(n):
    # Your code here
    pass

5 test cases · run your code against them in the editor