1987. Substrings of Size Three with Distinct Characters
My accepted Python solution to LeetCode problem 1987, Substrings of Size Three with Distinct Characters, running in 3ms.
- Difficulty: Easy
- Python
- Runtime 3ms
- Memory 17.2MB
- Updated
Read the problem on LeetCode View on GitHub
The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.
Python
Accepted on LeetCode — runtime 3ms, memory 17.2MB, accepted 2025-12-31.
class Solution:
def countGoodSubstrings(self, s: str) -> int:
count = 0
for i in range(len(s) - 2):
if len(set(s[i:i+3])) == 3:
count += 1
return count