LeetCode in Kotlin
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
class Solution {
fun countGoodSubstrings(s: String): Int {
var count = 0
for (i in 0 until s.length - 2) {
val candidate = s.substring(i, i + 3)
if (candidate[0] != candidate[1] && candidate[0] != candidate[2] && candidate[1] != candidate[2]) {
count++
}
}
return count
}
}