poj 2250 Compromise （DP-LCS 记录路径）

Compromise

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 6539		Accepted: 2929		Special Judge

Description

In a few months the European Currency Union will become a reality. However, to join the club, the Maastricht criteria must be fulfilled, and this is not a trivial task for the countries (maybe except for Luxembourg). To enforce that Germany will fulfill the
criteria, our government has so many wonderful options (raise taxes, sell stocks, revalue the gold reserves,...) that it is really hard to choose what to do.

Therefore the German government requires a program for the following task:

Two politicians each enter their proposal of what to do. The computer then outputs the longest common subsequence of words that occurs in both proposals. As you can see, this is a totally fair compromise (after all, a common sequence of words is something what
both people have in mind).

Your country needs this program, so your job is to write it for us.
Input

The input will contain several test cases.

Each test case consists of two texts. Each text is given as a sequence of lower-case words, separated by whitespace, but with no punctuation. Words will be less than 30 characters long. Both texts will contain less than 100 words and will be terminated by a
line containing a single '#'.

Input is terminated by end of file.
Output

For each test case, print the longest common subsequence of words occuring in the two texts. If there is more than one such sequence, any one is acceptable. Separate the words by one blank. After the last word, output a newline character.
Sample Input

die einkommen der landwirte
sind fuer die abgeordneten ein buch mit sieben siegeln
um dem abzuhelfen
muessen dringend alle subventionsgesetze verbessert werden
#
die steuern auf vermoegen und einkommen
sollten nach meinung der abgeordneten
nachdruecklich erhoben werden
dazu muessen die kontrollbefugnisse der finanzbehoerden
dringend verbessert werden
#

Sample Output

die einkommen der abgeordneten muessen dringend verbessert werden

大致题意：
刚开始看题，还以为是找出两段文字里出现的相同的单词输出，很神奇的觉得是字典树。。但题目一直说是LCS。。而且不甚理解为什么会有什么相同长度的字串任选一个输出。后来才发现是找两段文字中最长的公共单词串，那就和LCS几乎一样了。。因为最后要输出一个最长的单词串，所以在dp的过程中要记录路径。用1.2.3表示三种情况。