2010/9/24 Albert Y. C. Lai
On 10-09-23 04:57 PM, Andrew Coppin wrote:
If you think that sounds silly, ask some random person (not a computer programmer, just some random human) how find the sum of a list of numbers.
My reply: to sum 10 numbers, sum 9 numbers, then account for the 10th. More at: http://groups.google.com/group/comp.lang.functional/msg/51df24fbf33b7059
Ask some random person how to find page 314 in a book. No one replies "check the 1st page, check the 2nd page, check the 3rd page...". In fact, no one replies in words. Almost everyone shows you how to cut to the middle or the estimated weighted middle (if the book seems to have 1000 pages, they cut near the one-third point), then say "oh, before this" or "oh, after this", repeat. Almost everyone divides and conquers. Almost everyone recurses.
I am not a computer programmer.
(I know that someone is bound to think, "when confronted with the problem of summing numbers, some people think, 'I know, I will divide and conquer'. Now they have two problems of summing numbers.")
A computer scientist knows how to count the stars in the sky: simply count half of them then multiply by two. -- or something like that.