problem.txt

Given a string, find the length of the longest sub-string without repeating characters.

"abccabb" output will be 3 due to "abc" or "cab"


constraints
Is the string contiguous? Yes, look for a sub-string and not a sub-sequence.
contiguous means the characters are sequential and do not have breaks in between them.
sub-string vs sub-sequence : in a sub-string, the characters do not have breaks between them. e.g from "abcbbd", we get "abc" sub-string.
In sub-sequence, we can have have breaks between the characters e.g from  "abcbbd" we get "abcd" (skipped the repeating characters bb)

Does case sensitivity matter ? No, assume all the characters will be in lowercase.

Test cases
"abccabb" returns 3 because of abc or cab
"cccccc" returns 1
"" returns 0
"abcbda" returns 4 because of cbda