Thanks, Roger; I suspected Base (#.) was involved; I just didn't think of taking its inverse.
Interestingly, although the solution using Base seems closer to the content of the problem -- keeping things in the realm of integers instead of going back and forth to and from strings -- on my system with J8.01, the approach using strings is roughly 3 times slower and uses roughly 3 times as much space. On Fri, 7 Mar 2014 14:15:39 -0800, Roger Hui <rogerhui.can...@gmail.com> wrote: > ... > 10&#.^:_1 x converts a number to its decimal digits. Alternatively, > "."0":x would be shorter than what's on the video. But we quibble. > > 10&#.^:_1 ]!100x > 9 3 3 2 6 2 1 5 4 4 3 9 4 4 1 5 2 6 8 1 6 9 9 2 3 8 8 5 6 2 6 6 7 0 0 4 9 0 > ... > "."0": !100x > 9 3 3 2 6 2 1 5 4 4 3 9 4 4 1 5 2 6 8 1 6 9 9 2 3 8 8 5 6 2 6 6 7 0 0 4 9 0 > ... —— Murray Eisenberg mur...@math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 240 246-7240 (H) University of Massachusetts 710 North Pleasant Street Amherst, MA 01003-9305 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
