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""" | ||
Adler-32 is a checksum algorithm which was invented by Mark Adler in 1995. | ||
Compared to a cyclic redundancy check of the same length, it trades reliability for speed (preferring the latter). | ||
Adler-32 is more reliable than Fletcher-16, and slightly less reliable than Fletcher-32.[2] | ||
source: https://en.wikipedia.org/wiki/Adler-32 | ||
""" | ||
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def adler32(plain_text: str) -> str: | ||
""" | ||
Function implements adler-32 hash. | ||
Itterates and evaluates new value for each character | ||
>>> adler32('Algorithms') | ||
363791387 | ||
>>> adler32('go adler em all') | ||
708642122 | ||
""" | ||
MOD_ADLER = 65521 | ||
a = 1 | ||
b = 0 | ||
for plain_chr in plain_text: | ||
a = (a + ord(plain_chr)) % MOD_ADLER | ||
b = (b + a) % MOD_ADLER | ||
return (b << 16) | a |