"""
This algorithm (k=33) was first reported by Dan Bernstein many years ago in comp.lang.c
Another version of this algorithm (now favored by Bernstein) uses xor:
hash(i) = hash(i - 1) * 33 ^ str[i];
First Magic constant 33:
It has never been adequately explained.
It's magic because it works better than many other constants, prime or not.
Second Magic Constant 5381:
1. odd number
2. prime number
3. deficient number
4. 001/010/100/000/101 b
source: http://www.cse.yorku.ca/~oz/hash.html
"""
def djb2(s: str) -> int:
"""
Implementation of djb2 hash algorithm that
is popular because of it's magic constants.
>>> djb2('Algorithms')
3782405311
>>> djb2('scramble bits')
1609059040
"""
hash_value = 5381
for x in s:
hash_value = ((hash_value << 5) + hash_value) + ord(x)
return hash_value & 0xFFFFFFFF