题解 | #单词倒排#

import java.util.*;
// 使用builder -> list string -> builder的思路

// 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 line;
        List<String> ans = new ArrayList<>();
        StringBuilder verse = new StringBuilder();
        StringBuilder buff = new StringBuilder();
        while (in.hasNextLine()) {
            line = in.nextLine();
            if (line == null || line == "") break;
            for (int i = 0; i < line.length(); i++) {
                if ((line.charAt(i) >= 'a' && line.charAt(i) <= 'z' ) || (line.charAt(i) >= 'A' && line.charAt(i) <= 'Z')) {
                    buff.append(line.charAt(i));
                } else {
                    
                    ans.add(buff.toString());
                    // System.out.println(ans);
                    buff = new StringBuilder();
                }
                
            }
            ans.add(buff.toString());

            for (int i = ans.size() - 1; i >= 0; i--) {
                
                verse.append(ans.get(i));
                verse.append(" ");
            }
            System.out.println(verse.toString());
        }
        
    }
}