LeetCode-in-Java
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 <= 100sconsists of lowercase English letters.
Solution
public class Solution {
public int countGoodSubstrings(String s) {
int count = 0;
for (int i = 0; i < s.length() - 2; i++) {
String candidate = s.substring(i, i + 3);
if (candidate.charAt(0) != candidate.charAt(1)
&& candidate.charAt(0) != candidate.charAt(2)
&& candidate.charAt(1) != candidate.charAt(2)) {
count++;
}
}
return count;
}
}