[MEDIUM] #1876 - Substrings of Size Three with Distinct Characters

[hackdartstorm]

Program 1876: Substrings of Size Three with Distinct Characters

Difficulty: Medium
Category: String

Task: Count good substrings of size 3

Input: s
Expected Output: Count

Submit: exercises/1000_programs/medium/1876_good_substrings.py

[Smithech]

I have proposed a solution to this issue in the PR #2684