You forgot one corner case: 
my $s1 = "1,0,CTGCCACCGCTGT";
my $s2 = "1,5,ACCG";

[download]
Apart from that, our solutions are identical-but your code is nicer I must admit ;)

In reply to Re^2: Intersecting Two Strings by lima1
in thread Intersecting Two Strings by Anonymous Monk

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