#3803

Count Residue Prefixes

easy · 65.4% accepted · 62 likes · top 70%

hash table · string

⊣ practice⊣ open on leetcode ↗

Description

You are given a string s consisting only of lowercase English letters.

A prefix of s is called a residue if the number of distinct characters in the prefix is equal to len(prefix) % 3.

Return the count of residue prefixes in s.

A prefix of a string is a non-empty substring that starts from the beginning of the string and extends to any point within it.

Solution