Problem

Assort Health wants to deduplicate short call transcript snippets before downstream review. Given a list of lowercase strings, group together all strings that are anagrams of each other and return the groups.

Two strings belong in the same group if they contain exactly the same characters with the same frequencies, regardless of order. Implement an algorithm that efficiently groups all such strings.

Formal Specification

• Input: transcripts, a list of lowercase strings
• Output: A list of groups, where each group is a list of strings that are anagrams of one another
• Strings may be returned in any order, and groups may be returned in any order

Examples

Example 1

• Input: transcripts = ["listen", "silent", "enlist", "rat", "tar", "art"]
• Output: [["listen", "silent", "enlist"], ["rat", "tar", "art"]]
• Explanation: Each group contains strings with identical character counts.

Example 2

• Input: transcripts = ["", "", "abc", "bca", "xyz"]
• Output: [["", ""], ["abc", "bca"], ["xyz"]]
• Explanation: Empty strings are anagrams of each other, and "abc" and "bca" share the same letters.

Constraints

• 1 <= len(transcripts) <= 10^4
• 0 <= len(transcripts[i]) <= 100
• transcripts[i] contains only lowercase English letters