Asp Forum - [QUIZ] One-Liners (#113

James Gray

2/9/2007 5:00:00 PM

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1. Please do not post any solutions or spoiler discussion for this quiz until
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This week's Ruby Quiz is in pop quiz format. For each of the scenarios below,
send in a one line (80 characters or less) solution that performs the task. You
may use any legal Ruby syntax including require statements and semicolons, but
the goal in finesse more than golfing.

Any input described in the problem is in a local variable called quiz.
Assigning to this variable is assumed to have happened earlier in the program
and is not part of your submitted solution.

Your line just needs to evaluate to the expected result. You do not have to
store the result in a variable or create any output.

Any edge cases not covered by the provided examples are left to your best
judgement.

* Given a Numeric, provide a String representation with commas inserted between
each set of three digits in front of the decimal. For example, 1999995.99
should become "1,999,995.99".

* Given a nested Array of Arrays, perform a flatten()-like operation that
removes only the top level of nesting. For example, [1, [2, [3]]] would become
[1, 2, [3]].

* Shuffle the contents of a provided Array.

* Given a Ruby class name in String form (like
"GhostWheel::Expression::LookAhead"), fetch the actual class object.

* Insert newlines into a paragraph of prose (provided in a String) so lines will
wrap at 40 characters.

* Given an Array of String words, build an Array of only those words that are
anagrams of the first word in the Array.

* Convert a ThinkGeek t-shirt slogan (in String form) into a binary
representation (still a String). For example, the popular shirt "you are dumb"
is actually printed as:

111100111011111110101
110000111100101100101
1100100111010111011011100010

* Provided with an open File object, select a random line of content.

* Given a wondrous number Integer, produce the sequence (in an Array). A
wondrous number is a number that eventually reaches one, if you apply the
following rules to build a sequence from it. If the current number in the
sequence is even, the next number is that number divided by two. When the
current number is odd, multiply that number by three and add one to get the next
number in the sequence. Therefore, if we start with the wondrous number 15, the
sequence is [15, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2,
1].

* Convert an Array of objects to nested Hashes such that %w[one two three four
five] becomes {"one" => {"two" => {"three" => {"four" => "five"}}}}.

33 Answers

James Gray

2/9/2007 7:46:00 PM

On Feb 9, 2007, at 1:40 PM, Robert Dober wrote:

> On 2/9/07, Ruby Quiz <james@grayproductions.net> wrote:
>>
>> The three rules of Ruby Quiz:
>>
>> <snip>
>>
> Sounds like fun,
> Now the stupid question of the day: will a comment before the line
> be a
> problem for your tools, I guess they are counting ;)

I don't have any tools. Someone should build a test suite and post
it though, if they feel motivated to do so.

For my solutions though, I put the questions as comments before each
solution.

James Edward Gray II

James Gray

2/9/2007 9:06:00 PM

On Feb 9, 2007, at 3:01 PM, Luke Ivers wrote:

> So, does the quiz variable that we're getting have to remain
> unmodified, or
> does it matter?

Either way is fine with me.

James Edward Gray II

James Gray

2/9/2007 9:15:00 PM

On Feb 9, 2007, at 3:10 PM, Luke Ivers wrote:

>>
>> * Given a wondrous number Integer, produce the sequence (in an
>> Array). A
>> wondrous number is a number that eventually reaches one, if you
>> apply the
>> following rules to build a sequence from it. If the current
>> number in the
>> sequence is even, the next number is that number divided by two.
>> When the
>> current number is odd, multiply that number by three and add one
>> to get
>> the next
>> number in the sequence. Therefore, if we start with the wondrous
>> number
>> 15, the
>> sequence is [15, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5,
>> 16, 8,
>> 4, 2,
>> 1].
>>
>>
> One final question: you say "given a wondrous number"... does this
> mean that
> the input is guaranteed to be wondrous, and we therefore don't need
> to check
> it...

Correct.

James Edward Gray II

Jamie Macey

2/9/2007 9:20:00 PM

On 2/9/07, James Edward Gray II <james@grayproductions.net> wrote:
> Someone should build a test suite and post
> it though, if they feel motivated to do so.

Okay. The only one I'm taking significant liberties with is the
random-line-from-a-file - the test is expecting that the contents of
the file be loaded using File#read, and uses OpenStruct to provide a
test stub with that functionality. Other than that, these tests are a
pretty direct translation from the initial description. Method stubs
for the implementation are also provided.

require 'test/unit'
require 'ostruct'

class OneLiner
class << self
def commaize(number)
end

def flatten_once(ary)
end

def shuffle(ary)
end

def get_class(name)
end

def wrap_text(paragraph)
end

def find_anagrams(words)
end

def binarize(slogan)
end

def random_line(file)
end

def wondrous_sequence(n)
end

def nested_hash(ary)
end
end
end

class TestOneLiner < Test::Unit::TestCase
# Given a Numeric, provide a String representation with commas inserted
# between each set of three digits in front of the decimal. For example,
# 1999995.99 should become "1,999,995.99".
def test_commaize
assert_equal "1,999,995.99", OneLiner.commaize(1999995.99)
end

# Given a nested Array of Arrays, perform a flatten()-like operation that
# removes only the top level of nesting. For example, [1, [2, [3]]] would
# become [1, 2, [3]].
def test_flatten_once
ary = [1, [2, [3, 4]]]
flatter_ary = [1, 2, [3, 4]]
assert_equal flatter_ary, OneLiner.flatten_once(ary)
end

# Shuffle the contents of a provided Array.
def test_shuffle
ary = [3,1,4,1,5,9]
shuffled_ary = OneLiner.shuffle(ary)
assert_not_equal ary, shuffled_ary
assert_equal ary.sort, shuffled_ary.sort
end

# Given a Ruby class name in String form (like
# "GhostWheel::Expression::LookAhead"), fetch the actual class object.
def test_get_class
assert_equal Test::Unit::TestCase,
OneLiner.get_class("Test::Unit::TestCase")
end

# Insert newlines into a paragraph of prose (provided in a String) so
# lines will wrap at 40 characters.
def test_wrap_text
wrapped = "Insert newlines into a paragraph of " + "\n" +
"prose (provided in a String) so lines " + "\n" +
"will wrap at 40 characters."
paragraph = "Insert newlines into a paragraph of " +
"prose (provided in a String) so lines " +
"will wrap at 40 characters."
assert_equal wrapped, OneLiner.wrap_text(paragraph)
end

# Given an Array of String words, build an Array of only those words that
# are anagrams of the first word in the Array.
def test_find_anagrams
anagrams = %w(cat act)
assert_equal anagrams, OneLiner.find_anagrams(%w(tac bat cat rat act))
end

# Convert a ThinkGeek t-shirt slogan (in String form) into a binary
# representation (still a String). For example, the popular shirt
# "you are dumb" is actually printed as:
# 111100111011111110101
# 110000111100101100101
# 1100100111010111011011100010
def test_binarize
output = "111100111011111110101" + "\n" +
"110000111100101100101" + "\n" +
"1100100111010111011011100010"
assert_equal output, OneLiner.binarize("you are dumb")
end

# Provided with an open File object, select a random line of content.
#
# NOTE: This test assumes you're using File#read to get the string data
# from the file - if doing otherwise, update the test?
def test_random_line
file = OpenStruct.new(:read => "development:
adapter: mysql
database: redvase_development
host: localhost
username: root
password:")
lines = file.read.split("\n")
line = OneLiner.random_line(file)
assert_equal true, lines.include?(line)
end

# Given a wondrous number Integer, produce the sequence (in an Array). A
# wondrous number is a number that eventually reaches one, if you apply
# the following rules to build a sequence from it. If the current number
# in the sequence is even, the next number is that number divided by two.
# When the current number is odd, multiply that number by three and add
# one to get the next number in the sequence. Therefore, if we start with
# the wondrous number 15, the sequence is [15, 46, 23, 70, 35, 106, 53,
# 160, 80, 40, 20, 10, 5, 16, 8, 4, 2, 1].
def test_wondrous_sequence
seq = [23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2, 1]
assert_equal seq, OneLiner.wondrous_sequence(23)
end

# Convert an Array of objects to nested Hashes such that %w[one two three
# four five] becomes {"one" => {"two" => {"three" => {"four" => "five"}}}}.
def test_nested_hash
hash = {:o => {:t => {:t => {:f => :f}}}}
assert_equal hash, OneLiner.nested_hash([:o, :t, :t, :f, :f])
end
end

James Gray

2/9/2007 9:27:00 PM

On Feb 9, 2007, at 3:19 PM, Jamie Macey wrote:

> On 2/9/07, James Edward Gray II <james@grayproductions.net> wrote:
>> Someone should build a test suite and post
>> it though, if they feel motivated to do so.
>
> Okay. The only one I'm taking significant liberties with is the
> random-line-from-a-file - the test is expecting that the contents of
> the file be loaded using File#read...

What if it's a file too big to read into memory? ;)

James Edward Gray II

Gavin Kistner

2/9/2007 9:52:00 PM

On Feb 9, 10:00 am, Ruby Quiz <j...@grayproductions.net> wrote:
> * Given a wondrous number Integer, produce the sequence (in an Array). A
> wondrous number is a number that eventually reaches one, if you apply the
> following rules to build a sequence from it. If the current number in the
> sequence is even, the next number is that number divided by two. When the
> current number is odd, multiply that number by three and add one to get the next
> number in the sequence. Therefore, if we start with the wondrous number 15, the
> sequence is [15, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2,
> 1].

Here are a few more test cases, both to help others and to be sure
that mine is right:

def test_wondrous( str )
maps = [
[1, [1]],
[3,[3,10,5,16,8,4,2,1]],
[5,[5,16,8,4,2,1]],
[8,[8,4,2,1]],
[15,[15,46,23,70,35,106,53,160,80,40,20,10,5,16,8,4,2,1]],
[31,
[31,94,47,142,71,214,107,322,161,484,242,121,364,182,91,274,137,412,206,103,310,155,466,233,700,350,175,526,263,790,395,1186,593,1780,890,445,1336,668,334,167,502,251,754,377,1132,566,283,850,425,1276,638,319,958,479,1438,719,2158,1079,3238,1619,4858,2429,7288,3644,1822,911,2734,1367,4102,2051,6154,3077,9232,4616,2308,1154,577,1732,866,433,1300,650,325,976,488,244,122,61,184,92,46,23,70,35,106,53,160,80,40,20,10,5,16,8,4,2,1]]
]
raise "Solution too long (#{str.length} characters)" unless
str.length <= 80
maps.each{ |pair|
quiz = pair[0]
expected = pair[1]
output = eval( str )
unless expected==output
raise "quiz=#{quiz}; expected #{expected.inspect}, got
#{output.inspect}"
end
}
end

Chris Shea

2/9/2007 10:05:00 PM

[snip]
> # Given an Array of String words, build an Array of only those words that
> # are anagrams of the first word in the Array.
> def test_find_anagrams
> anagrams = %w(cat act)
> assert_equal anagrams, OneLiner.find_anagrams(%w(tac bat cat rat act))
> end
[snip]

I changed anagrams to %w(tac cat act). I'm the sort of person that
thinks a word is an anagram of itself (although, I have a feeling
"tac" isn't a word).

Gavin Kistner

2/9/2007 10:15:00 PM

On Feb 9, 10:00 am, Ruby Quiz <j...@grayproductions.net> wrote:
> * Given a Numeric, provide a String representation with commas inserted between
> each set of three digits in front of the decimal. For example, 1999995.99
> should become "1,999,995.99".

More test cases:
def test_commify( str )
maps = [
[1, "1"],
[-1, "-1"],
[0.001, "0.001"],
[-0.001, "-0.001"],
[999, "999"],
[-999, "-999"],
[999.1, "999.1"],
[-999.1, "-999.1"],
[999.12, "999.12"],
[-999.12, "-999.12"],
[999.123, "999.123"],
[-999.123, "-999.123"],
[9999, "9,999"],
[-9999, "-9,999"],
[9999.1, "9,999.1"],
[-9999.1, "-9,999.1"],
[9999.12, "9,999.12"],
[-9999.12, "-9,999.12"],
[9999.123, "9,999.123"],
[-9999.123, "-9,999.123"],
[12, "12"],
[123, "123"],
[1234, "1,234"],
[12345, "12,345"],
[123456, "123,456"],
[1234567, "1,234,567"],
[12345678, "12,345,678"],
[-12, "-12"],
[-123, "-123"],
[-1234, "-1,234"],
[-12345, "-12,345"],
[-123456, "-123,456"],
[-1234567, "-1,234,567"],
[-12345678, "-12,345,678"]
]
raise "Solution too long (#{str.length} characters)" unless
str.length <= 80
maps.each{ |pair|
quiz = pair[0]
expected = pair[1]
output = eval( str )

unless expected==output
raise "quiz=#{quiz}; expected #{expected.inspect}, got
#{output.inspect}"
end
}
end

Jamie Macey

2/9/2007 10:17:00 PM

On 2/9/07, Chris Shea <cmshea@gmail.com> wrote:
> [snip]
> > # Given an Array of String words, build an Array of only those words that
> > # are anagrams of the first word in the Array.
> > def test_find_anagrams
> > anagrams = %w(cat act)
> > assert_equal anagrams, OneLiner.find_anagrams(%w(tac bat cat rat act))
> > end
> [snip]
>
> I changed anagrams to %w(tac cat act). I'm the sort of person that
> thinks a word is an anagram of itself (although, I have a feeling
> "tac" isn't a word).

Neither did I, I was just looking for an easy test. And yet, lo and behold:

http://cancerweb.ncl.ac.uk/cgi-bin/omd...
A kind of customary payment by a tenant; a word used in old records.
Origin: Cf. Tack, 4.
Source: Websters Dictionary

Gavin Kistner

2/9/2007 10:42:00 PM

On Feb 9, 10:00 am, Ruby Quiz <j...@grayproductions.net> wrote:
> * Given a nested Array of Arrays, perform a flatten()-like operation that
> removes only the top level of nesting. For example, [1, [2, [3]]] would become
> [1, 2, [3]].

Yet more test cases (and a new way that I'm testing them). Used like:
s = 'your 80 char solution here'
test_solution( :flatten_once, s )

def test_solution( map_set, str )
raise "Solution too long (#{str.length} chars)" unless str.length <=
80
maps = MAPS[ map_set ]
maps.each{ |pair|
quiz = pair[0]
expected = pair[1]
output = eval( str )

unless expected==output
raise "quiz=#{quiz}; expected #{expected.inspect}, got
#{output.inspect}"
end
}
end

MAPS = {
:commify => [
[1, "1"],
[-1, "-1"],
[0.001, "0.001"],
[-0.001, "-0.001"],
[999, "999"],
[-999, "-999"],
[999.1, "999.1"],
[-999.1, "-999.1"],
[999.12, "999.12"],
[-999.12, "-999.12"],
[999.123, "999.123"],
[-999.123, "-999.123"],
[9999, "9,999"],
[-9999, "-9,999"],
[9999.1, "9,999.1"],
[-9999.1, "-9,999.1"],
[9999.12, "9,999.12"],
[-9999.12, "-9,999.12"],
[9999.123, "9,999.123"],
[-9999.123, "-9,999.123"],
[12, "12"],
[123, "123"],
[1234, "1,234"],
[12345, "12,345"],
[123456, "123,456"],
[1234567, "1,234,567"],
[12345678, "12,345,678"],
[-12, "-12"],
[-123, "-123"],
[-1234, "-1,234"],
[-12345, "-12,345"],
[-123456, "-123,456"],
[-1234567, "-1,234,567"],
[-12345678, "-12,345,678"]
],

:flatten_once => [
[ [], [] ],
[ [1], [1] ],
[ [1,2], [1,2] ],
[ [1,[2]], [1,2] ],
[ [[1],2], [1,2] ],
[ [[1,2]], [1,2] ],
[ [1,2,3], [1,2,3] ],
[ [1,[2,3]], [1,2,3] ],
[ [[1,2,3]], [1,2,3] ],
[ [1, [2, [3]]], [1, 2, [3]] ],
[ [1, [[2], 3]], [1, [2], 3] ],
[ [1,[2,[3,[4]]]], [1, 2, [3,[4]]] ],
[ [[[[[[6]]]]]], [[[[[6]]]]] ]
],

:wondrous => [
[1, [1]],
[3,[3,10,5,16,8,4,2,1]],
[5,[5,16,8,4,2,1]],
[8,[8,4,2,1]],
[15,[15,46,23,70,35,106,53,160,80,40,20,10,5,16,8,4,2,1]],
[31,
[31,94,47,142,71,214,107,322,161,484,242,121,364,182,91,274,137,412,206,103,310,155,466,233,700,350,175,526,263,790,395,1186,593,1780,890,445,1336,668,334,167,502,251,754,377,1132,566,283,850,425,1276,638,319,958,479,1438,719,2158,1079,3238,1619,4858,2429,7288,3644,1822,911,2734,1367,4102,2051,6154,3077,9232,4616,2308,1154,577,1732,866,433,1300,650,325,976,488,244,122,61,184,92,46,23,70,35,106,53,160,80,40,20,10,5,16,8,4,2,1]]
]

}

comp.lang.ruby

[QUIZ] One-Liners (#113

James Gray

James Gray

James Gray

James Gray

Jamie Macey

James Gray

Gavin Kistner

Chris Shea

Gavin Kistner

Jamie Macey

Gavin Kistner

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