思路
1、该问题可以直接利用字符串包含不包含,截取
import java.util.*;
public class Main{
public static void main(String agrs[]) {
Scanner sc = new Scanner(System.in);
String line = sc.nextLine();
String result = "";
for (int i = line.length(); i > 0; i--) {
if (!result.contains(line.substring(i-1,i))) {
result += line.substring(i-1,i);
}
}
System.out.println(result);
}
}