If I understand your question correctly, you want to know how many subsequences are in a given sequence? So for a S1="abcde" you can have subsequences of a,ab,abc,abcd,abcde,b,bc,bcd,bcde,c,cd,cde,d,de,e. Is that right?

Then it's a straight function of length. Because a subsequence can start on any letter and run from between 1 character until the rest of the length long.

In the previous example the sequence is 5 long. And there are 5 subsequences beginning with a. There are 4 subsequences starting with b. 3 with c and so on. Number of subsequences: 5 + 4 + 3 + 2 + 1

So the number of subsequences is the sum from 1 to length. 1 + 2 + 3 + . . . + lengthOfString = # of subsequences.

--
I used to drive a Heisenbergmobile, but every time I looked at the speedometer, I got lost.

In reply to Re: True Brute Force Longest Common Sub Sequence by KurtSchwind
in thread True Brute Force Longest Common Sub Sequence by Anonymous Monk

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