题解 | #提取不重复的整数#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        if(str.endsWith("0") || str=="" || str.length()==0){
            return;
        }
        char[] charArr = str.toCharArray();
        StringBuilder sb = new StringBuilder();
        for(int i=charArr.length-1; i>=0; i--){
            char item = charArr[i];
            if(sb.toString().contains(String.valueOf(item))){
                //contains()参数必须为string
                continue;
            }
            sb.append(item);
        }
        System.out.println(sb.toString());
    }
}