uva10391

maksyuki 发表于 oj 分类,标签:
0

You are to find all the two-word compound words in a dictionary. A two-word compound word is a word in the dictionary that is the concatenation of exactly two other words in the dictionary.

Input

Standard input consists of a number of lowercase words, one per line, in alphabetical order. There will be no more than 120,000 words.

Output

Your output should contain all the compound words, one per line, in alphabetical order.

Sample Input

a
alien
born
less
lien
never
nevertheless
new
newborn
the
zebra

Sample Output

alien

newborn

 

题目类型:二分查找

算法分析:由于数据规模有12e4,所以考虑按照字典序对于每个单词构造出其相接的子串sa和sb,然后二分查找sa和sb是否在给定的数据集中,复杂度为O(nmlogn),n为单词个数,m为单词长度