题解 | 提取不重复的整数

import java.util.*;

// 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);
        String str = new StringBuffer(in.next()).reverse().toString();
        char[] ch = str.toCharArray();
        for (int i = 0; i < ch.length; i++) {
            if (ch[i] == ' ') {
                continue;
            }
            for (int j = i + 1; j < ch.length; j++) {
                if (ch[i] == ch[j]) {
                    ch[j] = ' ';
                }
            }
        }

        for (int i = 0; i < ch.length; i++) {
            if (ch[i] != ' ') {
                System.out.print(ch[i]);
            }
        }
    }
}