Comments on: “The numbers don’t tally!” – a serial counting problem http://polymathprogrammer.com/2009/10/05/the-numbers-dont-tally-serial-counting-problem/ Where entrepreneurship, mathematics and programming meet Wed, 28 Mar 2012 04:44:06 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Vincent http://polymathprogrammer.com/2009/10/05/the-numbers-dont-tally-serial-counting-problem/comment-page-1/#comment-8524 Vincent Thu, 11 Feb 2010 12:23:46 +0000 http://polymathprogrammer.com/?p=1552#comment-8524 Will, the farmer might be exercising artistic creativity. "There should be 6 fenceposts! You left out one at that end!" "I wanted to express the concept of never-ending in my own way. So I deliberately left the end post out." "Oh you're just being cheap..." "If you say so..." Will, the farmer might be exercising artistic creativity.

“There should be 6 fenceposts! You left out one at that end!”
“I wanted to express the concept of never-ending in my own way. So I deliberately left the end post out.”
“Oh you’re just being cheap…”
“If you say so…”

]]> By: Will Dwinnell http://polymathprogrammer.com/2009/10/05/the-numbers-dont-tally-serial-counting-problem/comment-page-1/#comment-8516 Will Dwinnell Thu, 11 Feb 2010 11:57:41 +0000 http://polymathprogrammer.com/?p=1552#comment-8516 I've heard this referred to as a "fencepost error", in reference to old questions like "A farmer wants to put up a 50 foot length of fence, with a fencepost every 10 feet. How many fenceposts will he need?" One natural response is to divide to get 5, but this of course neglects the very first fencepost. I’ve heard this referred to as a “fencepost error”, in reference to old questions like “A farmer wants to put up a 50 foot length of fence, with a fencepost every 10 feet. How many fenceposts will he need?” One natural response is to divide to get 5, but this of course neglects the very first fencepost.

]]> By: Vincent Tan http://polymathprogrammer.com/2009/10/05/the-numbers-dont-tally-serial-counting-problem/comment-page-1/#comment-5945 Vincent Tan Mon, 05 Oct 2009 16:44:48 +0000 http://polymathprogrammer.com/?p=1552#comment-5945 That's true. I remember reading a paper by a famous programmer. Donald Knuth? Bjarne Stroustrup? That person wrote a paper comparing the pros and cons of 0-indexing and 1-indexing, and finally concluded that 0-indexing is the most efficient or something. Maybe I read that from codinghorror.com or something... That’s true. I remember reading a paper by a famous programmer. Donald Knuth? Bjarne Stroustrup?

That person wrote a paper comparing the pros and cons of 0-indexing and 1-indexing, and finally concluded that 0-indexing is the most efficient or something.

Maybe I read that from codinghorror.com or something…

]]> By: Steve http://polymathprogrammer.com/2009/10/05/the-numbers-dont-tally-serial-counting-problem/comment-page-1/#comment-5944 Steve Mon, 05 Oct 2009 15:49:02 +0000 http://polymathprogrammer.com/?p=1552#comment-5944 In computer programming, this "0-based" versus "1-based" problem comes up often. For instance, in C, to define an int array with 10 elements, you use: int C[10] but the elements of C are C[0] (the 1st element), C[1] (the 2nd element), ... C[9] (the 10th element.) It's tempting to ask for the 10th element of C as C[10], but that's off by one. In fact, that's the title of the Wikipedia article about this issue: http://en.wikipedia.org/wiki/Off-by-one_error In computer programming, this “0-based” versus “1-based” problem comes up often. For instance, in C, to define an int array with 10 elements, you use:

int C[10]

but the elements of C are C[0] (the 1st element), C[1] (the 2nd element), … C[9] (the 10th element.) It’s tempting to ask for the 10th element of C as C[10], but that’s off by one. In fact, that’s the title of the Wikipedia article about this issue:

http://en.wikipedia.org/wiki/Off-by-one_error

]]> By: Vincent Tan http://polymathprogrammer.com/2009/10/05/the-numbers-dont-tally-serial-counting-problem/comment-page-1/#comment-5942 Vincent Tan Mon, 05 Oct 2009 13:43:20 +0000 http://polymathprogrammer.com/?p=1552#comment-5942 Ahh... so it's 0026 - 0006 (the serial number that's not there) Then again, due to improper (re)education, some of us forget how to count in our double digit years... ;) Ahh… so it’s 0026 – 0006 (the serial number that’s not there)

Then again, due to improper (re)education, some of us forget how to count in our double digit years… ;)

]]> By: Eric http://polymathprogrammer.com/2009/10/05/the-numbers-dont-tally-serial-counting-problem/comment-page-1/#comment-5940 Eric Mon, 05 Oct 2009 13:12:44 +0000 http://polymathprogrammer.com/?p=1552#comment-5940 This kind of counting problem can often be handled by reverting to the old "take away" concept that so many of us learned in our single digit years. What you should really be doing to count items in the inventory is to "take away" all the numbers that aren't there; don't take away the first number that is. This kind of counting problem can often be handled by reverting to the old “take away” concept that so many of us learned in our single digit years. What you should really be doing to count items in the inventory is to “take away” all the numbers that aren’t there; don’t take away the first number that is.

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