[Numpy-discussion] Faster

[Hoyt Koepke]

>  and then update the others only if the row you're updating has that
>  minimum value in it.  Then, when scanning for the min dist, you only
>  need to scan O(n) rows.

Sorry, let me clarify -- Update the entries corresponding to entries
in the row you're updating if they are the same as the minimum
distance; in that case you need to rescan the row.  Also, ySorry, ou
only need to scan O(n) entries in your cached array.