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diff --git a/js/games/nluqo.github.io/~bh/ssch14/number-name.html b/js/games/nluqo.github.io/~bh/ssch14/number-name.html new file mode 100644 index 0000000..bac8cd1 --- /dev/null +++ b/js/games/nluqo.github.io/~bh/ssch14/number-name.html @@ -0,0 +1,91 @@ +<P> + +<P> +<HTML> +<HEAD> +<TITLE>Simply Scheme:Project: Spelling Names of Huge Numbers</TITLE> +</HEAD> +<BODY> +<CITE>Simply Scheme</CITE>: +<CITE>Introducing Computer Science</CITE> 2/e Copyright (C) 1999 MIT +<H1>Project: Spelling Names of Huge Numbers</H1> + +<TABLE width="100%"><TR><TD> +<IMG SRC="../simply.jpg" ALT="cover photo"> +<TD><TABLE> +<TR><TD align="right"><CITE><A HREF="http://www.cs.berkeley.edu/~bh/">Brian +Harvey</A><BR>University of California, Berkeley</CITE> +<TR><TD align="right"><CITE><A HREF="http://ccrma.stanford.edu/~matt">Matthew +Wright</A><BR>University of California, Santa Barbara</CITE> +<TR><TD align="right"><BR> +<TR><TD align="right"><A HREF="../pdf/ssch14.pdf">Download PDF version</A> +<TR><TD align="right"><A HREF="../ss-toc2.html">Back to Table of Contents</A> +<TR><TD align="right"><A HREF="recur-patterns.html"><STRONG>BACK</STRONG></A> +chapter thread <A HREF="../ssch15/adv-recur.html"><STRONG>NEXT</STRONG></A> +<TR><TD align="right"><A HREF="http://mitpress.mit.edu/0262082810">MIT +Press web page for <CITE>Simply Scheme</CITE></A> +</TABLE></TABLE> + +<HR> + +<P> + + +<P>Write a procedure <CODE><A NAME="g1"></A>number-name</CODE> that takes a positive integer +argument and returns a sentence containing that number spelled out in words: + +<P><PRE>> (number-name 5513345) +(FIVE MILLION FIVE HUNDRED THIRTEEN THOUSAND THREE HUNDRED FORTY FIVE) + +> (number-name (factorial 20)) +(TWO QUINTILLION FOUR HUNDRED THIRTY TWO QUADRILLION NINE HUNDRED TWO + TRILLION EIGHT BILLION ONE HUNDRED SEVENTY SIX MILLION SIX HUNDRED + FORTY THOUSAND) +</PRE> + +<P>There are some special cases you will need to consider: + +<P><P><TABLE><TR><TH align="right" valign="top">•<TD> <TD valign="top">Numbers in which some particular digit is zero +</TABLE><TABLE><TR><TH align="right" valign="top">•<TD> <TD valign="top">Numbers like 1,000,529 in which an entire group of three digits is zero. +</TABLE><TABLE><TR><TH align="right" valign="top">•<TD> <TD valign="top">Numbers in the teens. + +</TABLE><P> + +<P>Here are two hints. First, split the number into groups of three digits, +going from right to left. Also, use the sentence + +<P><PRE>'(thousand million billion trillion quadrillion quintillion + sextillion septillion octillion nonillion decillion) +</PRE> + +<P>You can write this bottom-up or top-down. To work bottom-up, pick a subtask +and get that working before you tackle the overall structure of the +problem. For example, write a procedure that returns the word <CODE>FIFTEEN</CODE> +given the argument <CODE>15</CODE>. + +<P>To work top-down, start by writing <CODE>number-name</CODE>, freely assuming the +existence of whatever helper procedures you like. You can begin debugging +by writing <EM>stub</EM> procedures that fit into the overall program but +don't really do their job correctly. For example, as an intermediate stage +you might end up with a program that works like this: + +<P><PRE>> (number-name 1428425) ;; intermediate version +(1 MILLION 428 THOUSAND 425) +</PRE> + + +<P> + + +<HR> +<P><A HREF="../ss-toc2.html">(back to Table of Contents)</A><P> +<A HREF="recur-patterns.html"><STRONG>BACK</STRONG></A> +chapter thread <A HREF="../ssch15/adv-recur.html"><STRONG>NEXT</STRONG></A> + +<P> +<ADDRESS> +<A HREF="../index.html">Brian Harvey</A>, +<CODE>bh@cs.berkeley.edu</CODE> +</ADDRESS> +</BODY> +</HTML> |