字典树-HDOJ-1247-Hat’s Words

Hat’s Words

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 8482    Accepted Submission(s): 3053

Problem Description

A hat’s word is a word in the dictionary that is the concatenation of exactly two other words in the dictionary.

You are to find all the hat’s words in a dictionary.

 

Input

Standard input consists of a number of lowercase words, one per line, in alphabetical order. There will be no more than 50,000 words.

Only one case.

 

Output

Your output should contain all the hat’s words, one per line, in alphabetical order.

 

Sample Input

a
ahat
hat
hatword
hziee
word

 

Sample Output

ahat
hatword

 

大意：给定若干个字符串，找出这种字符串——它可由其它两个字符串拼接得到。

分析：考虑两种特殊情况：

input-----

a

bc

ab

c

abc

output----

abc

input-----

b

ba

baab

baabb

output----

baabb