题解 | #提取不重复的整数#

利用到了StringBuilder的反转方法，和linkedHashSet的有序和去重的特点。老API调用工程师了

public class Main {

        public static void main(String[] args){
            Scanner s = new Scanner(System.in);
            String line = s.nextLine();
            StringBuilder builder = new StringBuilder(line);
            builder.reverse();//反转字符串
            char[] chars = builder.toString().toCharArray();
            Set<Character> linkSet = new LinkedHashSet<>();//去重有序
            for (char aChar : chars) {
                linkSet.add(aChar);
            }
            for (Character character : linkSet) {
                System.out.print(character);
            }
        }
}