README.md

1876. Substrings of Size Three with Distinct Characters

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.

Solutions (Rust)

1. Solution

impl Solution {
    pub fn count_good_substrings(s: String) -> i32 {
        s.into_bytes()
            .windows(3)
            .filter(|gs| gs[0] != gs[1] && gs[0] != gs[2] && gs[1] != gs[2])
            .count() as i32
    }
}