Given an array of integers arr and two integers k and threshold, return the number of sub-arrays of size k and average greater than or equal to threshold.
The k-beauty of an integer num is defined as the number of substrings of num when it is read as a string that meet the following conditions:
A string s is nice if, for every letter of the alphabet that s contains, it appears both in uppercase and lowercase. For example, “abABB” is nice because ‘A’...
You have a bomb to defuse, and your time is running out! Your informer will provide you with a circular array code of length of n and a key k.
A string is good if there are no repeated characters.