题解 | 提取不重复的整数

import java.util.Scanner;

import java.util.Set;
import java.util.LinkedHashSet;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String str  = Integer.toString(n);
        StringBuilder sb  = new StringBuilder();
        for(int i = str.length()-1;i>=0;i--){
            sb.append(str.charAt(i));
        }
        Set<Character> set  = new LinkedHashSet<>();
        for(char c : sb.toString().toCharArray()){
            set.add(c);
        }
        
        StringBuilder result  = new StringBuilder();
        for(char c : set){
        result.append(c);
        }
         System.out.println(result.toString());
    }
   
}