To check if alternate bits are set, Carry out the following operations:

• First XOR the number n and (n >> 1). If alternate bits are set then this will produce all 1’s. Let us call the result as m
• To check is all the bits are set to 1, AND m with m + 1 and the result will be 0

Example:

Let us say n = 5.

n              101
(n >> 1)   010
———————   XOR
m             111

Now,

m              0111
m+1         1000
———————–  AND
result      0000