We present a new linear systolic array architecture of m cells which outputs a longest common subsequence (LCS) of two input strings A and B in time n + 2m, where n and m denote the lengths of A andB respectively (m n). Our approach improves the time of execution required by previous linear systolic arrays for this purpose. Furthermore, a design combining a tree with the linear array provides an LCS and its length in n + m + log m clock cycles only.