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 in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        String num = in.next();
        StringBuffer str = new StringBuffer();
        for(int i = num.length()-1; i >= 0;i--){
            char ch = num.charAt(i);
            if(ch == ' '){
                continue;
            }
		  	//去重
            num = num.replace(ch + ""," ");

            System.out.print(ch);
        }
    }
}