Merge branch 'master' of git://github.com/killy971/factor

db4
Slava Pestov 2009-10-13 17:09:35 -05:00
commit cc48dd5a8f
14 changed files with 148 additions and 12 deletions

View File

@ -0,0 +1,4 @@
USING: project-euler.065 tools.test ;
IN: project-euler.065.tests
[ 272 ] [ euler065 ] unit-test

View File

@ -0,0 +1,77 @@
! Copyright (c) 2009 Guillaume Nargeot.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel math lists lists.lazy project-euler.common sequences ;
IN: project-euler.065
! http://projecteuler.net/index.php?section=problems&id=065
! DESCRIPTION
! -----------
! The square root of 2 can be written as an infinite continued fraction.
! 1
! √2 = 1 + -------------------------
! 1
! 2 + ---------------------
! 1
! 2 + -----------------
! 1
! 2 + -------------
! 2 + ...
! The infinite continued fraction can be written, √2 = [1;(2)], (2) indicates
! that 2 repeats ad infinitum. In a similar way, √23 = [4;(1,3,1,8)].
! It turns out that the sequence of partial values of continued fractions for
! square roots provide the best rational approximations. Let us consider the
! convergents for √2.
! 1 3 1 7 1 17 1 41
! 1 + - = - ; 1 + ----- = - ; 1 + --------- = -- ; 1 + ------------- = --
! 2 2 1 5 1 12 1 29
! 2 + - 2 + ----- 2 + ---------
! 2 1 1
! 2 + - 2 + -----
! 2 1
! 2 + -
! 2
! Hence the sequence of the first ten convergents for √2 are:
! 1, 3/2, 7/5, 17/12, 41/29, 99/70, 239/169, 577/408, 1393/985, 3363/2378, ...
! What is most surprising is that the important mathematical constant,
! e = [2; 1,2,1, 1,4,1, 1,6,1 , ... , 1,2k,1, ...].
! The first ten terms in the sequence of convergents for e are:
! 2, 3, 8/3, 11/4, 19/7, 87/32, 106/39, 193/71, 1264/465, 1457/536, ...
! The sum of digits in the numerator of the 10th convergent is 1+4+5+7=17.
! Find the sum of digits in the numerator of the 100th convergent of the
! continued fraction for e.
! SOLUTION
! --------
<PRIVATE
: (e-frac) ( -- seq )
2 lfrom [
dup 3 mod zero? [ 3 / 2 * ] [ drop 1 ] if
] lazy-map ;
: e-frac ( n -- n )
1 - (e-frac) ltake list>array reverse 0
[ + recip ] reduce 2 + ;
PRIVATE>
: euler065 ( -- answer )
100 e-frac numerator number>digits sum ;
! [ euler065 ] 100 ave-time
! 4 ms ave run time - 0.33 SD (100 trials)
SOLUTION: euler065

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -30,7 +30,7 @@ IN: project-euler.072
! The answer can be found by adding totient(n) for 2 ≤ n ≤ 1e6 ! The answer can be found by adding totient(n) for 2 ≤ n ≤ 1e6
: euler072 ( -- answer ) : euler072 ( -- answer )
2 1000000 [a,b] [ totient ] [ + ] map-reduce ; 2 1000000 [a,b] [ totient ] sigma ;
! [ euler072 ] 100 ave-time ! [ euler072 ] 100 ave-time
! 5274 ms ave run time - 102.7 SD (100 trials) ! 5274 ms ave run time - 102.7 SD (100 trials)

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -0,0 +1,4 @@
USING: project-euler.188 tools.test ;
IN: project-euler.188.tests
[ 95962097 ] [ euler188 ] unit-test

View File

@ -0,0 +1,43 @@
! Copyright (c) 2009 Guillaume Nargeot.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel math math.functions project-euler.common ;
IN: project-euler.188
! http://projecteuler.net/index.php?section=problems&id=188
! DESCRIPTION
! -----------
! The hyperexponentiation or tetration of a number a by a positive integer b,
! denoted by a↑↑b or ^(b)a, is recursively defined by:
! a↑↑1 = a,
! a↑↑(k+1) = a^(a↑↑k).
! Thus we have e.g. 3↑↑2 = 3^3 = 27, hence
! 3↑↑3 = 3^27 = 7625597484987 and
! 3↑↑4 is roughly 10^(3.6383346400240996*10^12).
! Find the last 8 digits of 1777↑↑1855.
! SOLUTION
! --------
! Using modular exponentiation.
! http://en.wikipedia.org/wiki/Modular_exponentiation
<PRIVATE
: hyper-exp-mod ( a b m -- e )
1 rot [ [ 2dup ] dip swap ^mod ] times 2nip ;
PRIVATE>
: euler188 ( -- answer )
1777 1855 10 8 ^ hyper-exp-mod ;
! [ euler188 ] 100 ave-time
! 4 ms ave run time - 0.05 SD (100 trials)
SOLUTION: euler188

View File

@ -0,0 +1 @@
Guillaume Nargeot

View File

@ -16,15 +16,15 @@ USING: definitions io io.files io.pathnames kernel math math.parser
project-euler.045 project-euler.046 project-euler.047 project-euler.048 project-euler.045 project-euler.046 project-euler.047 project-euler.048
project-euler.049 project-euler.051 project-euler.052 project-euler.053 project-euler.049 project-euler.051 project-euler.052 project-euler.053
project-euler.054 project-euler.055 project-euler.056 project-euler.057 project-euler.054 project-euler.055 project-euler.056 project-euler.057
project-euler.058 project-euler.059 project-euler.063 project-euler.067 project-euler.058 project-euler.059 project-euler.063 project-euler.065
project-euler.069 project-euler.071 project-euler.072 project-euler.073 project-euler.067 project-euler.069 project-euler.071 project-euler.072
project-euler.074 project-euler.075 project-euler.076 project-euler.079 project-euler.073 project-euler.074 project-euler.075 project-euler.076
project-euler.085 project-euler.092 project-euler.097 project-euler.099 project-euler.079 project-euler.085 project-euler.092 project-euler.097
project-euler.100 project-euler.102 project-euler.112 project-euler.116 project-euler.099 project-euler.100 project-euler.102 project-euler.112
project-euler.117 project-euler.124 project-euler.134 project-euler.148 project-euler.116 project-euler.117 project-euler.124 project-euler.134
project-euler.150 project-euler.151 project-euler.164 project-euler.169 project-euler.148 project-euler.150 project-euler.151 project-euler.164
project-euler.173 project-euler.175 project-euler.186 project-euler.190 project-euler.169 project-euler.173 project-euler.175 project-euler.186
project-euler.203 project-euler.215 ; project-euler.188 project-euler.190 project-euler.203 project-euler.215 ;
IN: project-euler IN: project-euler
<PRIVATE <PRIVATE