Untitled

public class Solution {
    public int countGoodSubstrings(String s) {
        int n = s.length();
        if (n < 3) return 0;

        int count = 0;
        int i = 0, j = 2; // Fixed-size window of 3

        while (j < n) {
            // Check if the current substring has unique characters
            char a = s.charAt(i);
            char b = s.charAt(i + 1);
            char c = s.charAt(j);

            if (a != b && b != c && a != c) {
                count++;
            }

            // Slide the window
            i++;
            j++;
        }

        return count;
    }
}