演講摘要：
The longest common subsequence (LCS) has been studied for several decades. It can be widely applied in many areas, such as biosequence alignment, speech recognition, file comparison, text search, and plagiarism detection. There are also several variants on the LCS problem, such as sequence inclusion or exclusion, and merged LCS. The “diff” command of Unix OS, and “Compare it” software are based on the LCS algorithms.