_1047.java

packagecom.fishercoder.solutions.secondthousand;

importjava.util.Deque;
importjava.util.LinkedList;

publicclass_1047 {
publicstaticclassSolution1 {
publicStringremoveDuplicates(StringS) {
StringBuildersb = newStringBuilder(S);
for (inti = 0; i < S.length() - 1; i++) {
if (S.charAt(i) == S.charAt(i + 1)) {
returnremoveDuplicates(S.substring(0, i) + S.substring(i + 2));
 }
 }
returnsb.toString();
 }
 }

publicstaticclassSolution2 {
publicStringremoveDuplicates(Strings) {
Deque<Character> stack = newLinkedList<>();
for (charc : s.toCharArray()) {
if (!stack.isEmpty() && stack.peekLast() == c) {
stack.pollLast();
 } else {
stack.addLast(c);
 }
 }
StringBuildersb = newStringBuilder();
while (!stack.isEmpty()) {
sb.append(stack.pollLast());
 }
returnsb.reverse().toString();
 }
 }
}