_1100.java

packagecom.fishercoder.solutions.secondthousand;

importjava.util.HashSet;
importjava.util.Set;

publicclass_1100 {
publicstaticclassSolution1 {
publicintnumKLenSubstrNoRepeats(StringS, intK) {
intcount = 0;
Set<Character> set = newHashSet<>();
for (inti = 0; i <= S.length() - K; i++) {
Stringstring = S.substring(i, i + K);
booleaninvalid = false;
for (charc : string.toCharArray()) {
if (!set.add(c)) {
invalid = true;
break;
 }
 }
count += invalid ? 0 : 1;
set.clear();
 }
returncount;
 }
 }
}