public static void main(String[] args) {

System.out.println(removeDuplicates("deeedbbcccbdaa", 3));

}

public static String removeDuplicates(String s, int k) {

if (k > s.length()) {

return s;

}

char[] chars = s.toCharArray();

Stack<Character> input = new Stack<>();

for (int i = 0; i < chars.length; i++) {

input.push(chars[i]);

}

Stack<Character> result = new Stack<>();

char temp = input.pop();

int sameNum = 1;

while (!input.isEmpty()) {

if (input.peek() == temp) {

input.pop();

sameNum++;

} else {

for (int i = 0; i < sameNum; i++) {

result.push(temp);

}

temp = input.pop();

sameNum = 1;

}

if (sameNum == k) {

for (int i = 0; !result.isEmpty() && i < k-1; i++) {

input.push(result.pop());

}

temp = input.pop();

sameNum = 1;

}

}

for (int i = 0; i < sameNum; i++) {

result.push(temp);

}

StringBuilder stringBuilder = new StringBuilder();

while (!result.isEmpty()) {

stringBuilder.append(result.pop());

}

return stringBuilder.toString();

}