_1763.java

packagecom.fishercoder.solutions.secondthousand;

publicclass_1763 {
publicstaticclassSolution1 {
publicStringlongestNiceSubstring(Strings) {
Stringlongest = "";
for (inti = 0; i < s.length() - 1; i++) {
for (intj = i; j <= s.length(); j++) {
if (isNiceString(s.substring(i, j))) {
if (longest.length() < j - i) {
longest = s.substring(i, j);
 }
 }
 }
 }
returnlongest;
 }

privatebooleanisNiceString(Stringstr) {
int[] uppercount = newint[26];
int[] lowercount = newint[26];
for (charc : str.toCharArray()) {
if (Character.isUpperCase(c)) {
uppercount[Character.toLowerCase(c) - 'a']++;
 } else {
lowercount[c - 'a']++;
 }
 }
for (inti = 0; i < uppercount.length; i++) {
if (uppercount[i] > 0 && lowercount[i] > 0
 || (uppercount[i] == 0 && lowercount[i] == 0)) {
continue;
 } else {
returnfalse;
 }
 }
returntrue;
 }
 }
}