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q = 6 : There are no possible values of j , since 7/(9 + j ) > 0 . 8 for every positive in-
teger j . The same holds for every smaller value of q .
i = 2 : Here, p = 8, so we require q ≤ 8. Since the constraint ( q +1)/(9+ j ) ≥ 0 . 8 does not
depend on i , 7 we can use the analysis from the above case, but exclude the case q =
9. Thus, the only possible values of j and q when i = 2 are
(1) q = 8; j = 1.
(2) q = 8; j = 2.
(3) q = 7; j = 1.
i = 3 : Now, p = 7 and the constraints are q ≤ 7 and ( q + 1)/(9 + j ) ≥ 0 . 8. The only option
is q = 7 and j = 1.
Next, we must consider the case p < q . The additional constraint is
Again, consider each possible value of i .
i = 1 : Then p = 9, so we require q ≥ 10 and 10/( q + j ) ≥ 0 . 8. The possible values of q and
j are
(1) q = 10; j = 1.
(2) q = 10; j = 2.
(3) q = 11; j = 1.
i = 2 : Now, p = 10, so we require q ≥ 11 and 9/( q + j + 1) ≥ 0 . 8. there are no solutions,
since j must be a positive integer.
i = 3 : As for i = 2, there are no solutions.
When we accumulate the possible combinations of i , j , and q , we see that the set of index
buckets in which we must look forms a pyramid. Figure 3.15 shows the buckets in which
we must search. That is, we must look in those buckets ( x, j, q ) such that the i th symbol of
the string s is x , j is the position associated with the bucket and q the suffix length.
Figure 3.15 The buckets that must be examined to find possible matches for the string s = acdefghijk with J = 0.8
are marked with an x
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