Quadratic-time algorithm for a string constrained LCS problem

The problem of finding a longest common subsequence of two main sequences with some constraint that must be a substring of the result (STR-IC-LCS) was formulated recently. It is a variant of the constrained longest common subsequence problem. As the known algorithms for the STR-IC-LCS problem are cubic-time, the presented quadratic-time algorithm is significantly faster.

► We investigate a string constrained LCS problem.
► We propose the first quadratic-time algorithm for the problem.
► We point out a flaw in some literature algorithm for the related problem.