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1876. Substrings of Size Three with Distinct Characters (Easy)

A string is good if there are no repeated characters.

Given a string s​​​​​, return the number of good substrings of length three in s​​​​​​.

Note that if there are multiple occurrences of the same substring, every occurrence should be counted.

A substring is a contiguous sequence of characters in a string.

 

Example 1:

Input: s = "xyzzaz" Output: 1 Explanation: There are 4 substrings of size 3: "xyz", "yzz", "zza", and "zaz". The only good substring of length 3 is "xyz". 

Example 2:

Input: s = "aababcabc" Output: 4 Explanation: There are 7 substrings of size 3: "aab", "aba", "bab", "abc", "bca", "cab", and "abc". The good substrings are "abc", "bca", "cab", and "abc". 

 

Constraints:

• 1 <= s.length <= 100
• s​​​​​​ consists of lowercase English letters.

Related Topics

[Hash Table] [String] [Counting] [Sliding Window]

Hints

Hint 1

Try using a set to find out the number of distinct characters in a substring.