题解 | 单词倒排|链表头插法·单次分割

import java.util.Scanner;
import java.io.*;

class Node {
    String s ;
    Node next;
    Node(String s) {
        this.s = s;
    }
}

class DictSplit {

    int start;
    String str;

    DictSplit(String s) {
        this.str = s;
        start = 0;
    }


    public String next() {
        if (start >= str.length()) {
            return null;
        }
        int i = start;
        String ans = null;
        int wc = 0;
        while (i < str.length()) {
            char ch = str.charAt(i);
            if (ch >= 'A' && ch <= 'Z' || ch >= 'a' && ch <= 'z') {
                wc++;
            } else {
                if (wc > 0) {
                    ans = str.substring(start, start + wc);
                    start += wc;
                    break;
                } else {
                    start++;
                }
            }
            i++;
        }

        if (ans == null && start < str.length()) {
            ans = str.substring(start);
            start = str.length();
        }
        return ans;
    }
}
// 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) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        DictSplit ds = new DictSplit(br.readLine());
        br.close();
        String word = null;
        Node dummy = new Node(null);
        while ((word = ds.next()) != null) {
            Node t = new Node(word);
            t.next = dummy.next;
            dummy.next = t;
        }

        Node cursor = dummy.next;
        while (cursor != null) {
            System.out.print(cursor.s + " ");
            cursor = cursor.next;
        }
        System.out.println();
    }
}