Editing Longest common subsequence (section)

=== Reduce the comparison time ===
Most of the time taken by the naive algorithm is spent performing comparisons between items in the sequences.  For textual sequences such as source code, you want to view lines as the sequence elements instead of single characters.  This can mean comparisons of relatively long strings for each step in the algorithm.  Two optimizations can be made that can help to reduce the time these comparisons consume.