I was studying the Longest common substring problem using DP ...

LCS(s1--p, t1--q) = 1+ LCS(s1--p-1, t1--q-1) if s[p]=t[q]

                                 0 otherwise

This was the solution given in wikipedia... This would give an answer of 0 for the strings "to" and "tom" ... But, shouldnt it be 2 ?? the "to" matches with "to" in tom . But, it compares only the last character and gives the answer`