题解 | #提取不重复的整数#

import java.util.Scanner;

public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in);

    //逆序排列
    StringBuilder stringBuilder = new StringBuilder(scanner.nextLine()).reverse();
    String str = stringBuilder.toString();

    //结果集
    StringBuilder result = new StringBuilder();

    for (int i = 0; i < str.length(); i++) {
        if (str.indexOf(str.charAt(i)) == i) {
            result.append(str.charAt(i));
        }
    }
    System.out.println(result.toString());
}

}