题解 | #单词倒排#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        ArrayList<String> list = new ArrayList<>();
        char[] arr = line.toCharArray();
      
        // 截取连续字母的字符串
        int num = 0;
        for (int i = 0; i < arr.length; i++) {
            if (!Character.isLetter(arr[i])) {
                if (num > 0) {
                    list.add(line.substring(i - num, i));
                }
                num = 0;
                continue;
            }
            num++;
        }
        // 再获取最后一个字符串
        if (num > 0) {
            list.add(line.substring(line.length() - num));
        }
        
        Collections.reverse(list);
        System.out.println(String.join(" ", list));
    }
}