862. Unique Frequency String
A string s is considered good if no two different characters in s have the same frequency. Given a string s, determine the minimum number of characters that need to be deleted to make s a good string. The frequency of a character in a string is the number of times it appears in the string. For example, in the string "aab", the frequency of 'a' is 2, while the frequency of 'b' is 1.
A single line containing a string.
An integer representing the minimum number of deletions.
1 <= s.length <= 10^5