The mergesort version of sort in perl 5.8+ will do that as well as anything1 by just sorting in the new value, 

@known = sort byIndex @known;
@known = sort byIndex $newValue, @known;

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The quicksort of previous versions of perl is bad for this. It has a quadratic worst case for nearly sorted lists.

1 Actually not as good as a binary search for a single insertion point, which is O(logN). That is how you'd perform your own suggestion. As tachyon says, though, insertion with splice is still O(N/2).

After Compline,
Zaxo

In reply to Re: Insert Into a Sorted Array by Zaxo
in thread Insert Into a Sorted Array by ketema

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