Java反序遍历

Java

import java.util.ArrayList;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String s = in.nextLine();
        ArrayList<Character> charList = new ArrayList<>();
        char[] chars = s.toCharArray();
        boolean zero = true;
        for (int i = chars.length - 1; i >= 0; i--) {
            zero = zero && chars[i] == '0';
            if (zero) continue;
            if (!charList.contains(chars[i])) charList.add(chars[i]);
        }
        for (Character character : charList) {
            System.out.print(character);
        }
        in.close();
    }
}