I’m starting to get comfortable with bit manipulation and here’s another problem that I’ve solved in just a few amount of time.

class Solution {
fun hasAlternatingBits(n: Int): Boolean {
var temp = n
var pos = temp and 1
while(temp > 0){
val m = temp and 1
if(pos != m) return false

temp = temp shr 1
pos = pos xor 1
}

return true
}
}

Runtime: 0 ms, faster than 100.00% of Kotlin online submissions for Binary Number with Alternating Bits.
Memory Usage: 30.9 MB, less than 100.00% of Kotlin online submissions for Binary Number with Alternating Bits.


pos sets the expection. If it is 1, then it expects that the LSB is 1 or 0 otherwise. Again, we crawl bit by bit and flip the expected value. If the expected value and LSB does not match, then the number does not contain alternating bits.