The 3rd term is then 21 ('two one') because the second term consisted of two 1s. The list in haskell is viewed as a monad. It's generated by describing a series of digits as letters in plain English language. Numbers. However, this is still true for any base $\geq 4$. You can take any number as a starting number, and then follow this rule to produce next numbers. 3 -> 13, 33 -> 23, 12 -> 1112 -> 3112. 5 kyu. number systems using only two bits 0 and 1 instead of the usual ten digits 0,1,..,9). 0 characters ARGV is available via STDIN, joined on NULL. If we start with any digit d from 0 to 9 then d will remain indefinitely as the last digit of the sequence. The 2nd term is 11 ('one one') because the first term (1) consisted of a single 1. We look at this and say what we see. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? That is: look-and-say is like Fibonacci, just with 92 instead of 2. Simple Fun #299: Look And Say And Sum. 4 4 1 86% of 21 60 haspience. You simply ‘look-and-say’. Mathematics. Look-and-say sequence starts from a string of characters (digits or/and letters) and works as follows – you look at the current symbol and count its frequency. More precisely, I want to look at a few different binary number systems (i.e. In this view, a calculation with a list is a calculation that is uncertain about the result. Generalizing fold. Each term is constructed from its predecessor by stating the frequency and number of each group of like digits. In Haskell, there are several ways to handle data that is structured in this way. For example, if you look at "22a", you count "two twos" and "one a" so the next sequence element is "221a", and then you repeat this process. The Look & Say sequence is quite ea s y to understand. raw download clone embed report print Haskell 0.79 KB. Problem. I just took a look at John Conway’s video at Numberphile about the “look-and-say” sequence or as Conway called it “The Weird and Wonderful Chemistry of Audioactive Decay”. Train Next Kata. Hardy's taxi (generalized) 9 9 0 90% of 20 59 jakber. The Look-and-Say Sequence with Digits 1 and 2. Why? The legendary John H. Conway on properties he discovered within the so-called Look-and-Say Sequence. Print the first 20 elements of the Look and Say sequence. See the list of supported languages to know the extension of your language.. First, consider this definition of a function which adds its two arguments: add :: Integer -> Integer -> Integer add x y = x + y This is an example of a curried function. In this section, we look at several aspects of functions in Haskell. Association lists are handy because they are simple. The system is it checks the previous digit and counts the numbers. The two most common are association lists and the Map type provided by Data.Map module. The sequence starts plainly with a single digit 1: 1. The rules are as follows: Take any number you like. Closely related to the ternary version of the sequence is the sequence obtained by reading the previous term in the sequence, but with the restriction that you can never use a number larger than 2 (see A110393). Terms of even ranks are counts while odd ranks are figures. Look and say sequence generator. 16 16 8 85% of 62 170 myjinxin2015. We calculated the look and say sequence in a previous exercise, and mentioned there that the sequence has some fascinating mathematical properties.One of them is that, if L n is the number of digits in the n-th element of the sequence, then. The n-th term is constructed by reading the (n-1)-th term. Then "11" becomes "21", and so on. I would like to introduce look-and-say sequence at first. Haskell Java JavaScript PHP Python Ruby. Python has the notion of "duck typing", meaning "If it walks and talks like a duck, it's a duck!". For example, "1" becomes "11", because there is one "1". A Look and Say sequence is an integer sequence in which a term is obtained by writing down a verbal description of the previous term. Rules for Creating the Sequence . Viewed 579 times 5. Puzzles. //atom-haskell.github.io/ to get set up), TextMate, and Sub-lime Text. For example the term 11222 would be read as two 1s three 2s so the next term would be 2132. The 1st term is given as 1. The Haskell code will represent these sequences as lists of type [Int] all of the members of which are positive.2 (In this paper, the elements of a list will be Language is selected by the extension of the file. Now we have come to the list monad, and now it gets interesting. The first few numbers are 1, 11, 21, 1211, and 111221.The next number in the sequence is 312211, because the last one has "Three 1s, two 2s, and one 1".Given n, produce the n-th number in the sequence.The output will not be longer than 20,000 characters. The digits 1, 2 and 3 can (and unless starting with 22, all eventually must) appear as the number of digits of a group at the previous stage, e.g. The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The statement is not trivial, as the sequence is a sequence of numbers, each of which can have many digits, and it speaks about what new digits can appear in numbers as the sequence develops. 38 38 7 88% of 94 714 kyushiro 2 Issues Reported. If you use emacs I recommend installing Intero (https: //commercialhaskell.github.io/intero/). Typical actions include reading and setting global variables, writing files, reading input, and opening windows. Sequences. I explained it to my dog in about 10 seconds and she stayed focused the entire time. The “Look and Say” sequence, Sloane number A005150, begins 1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, …. It is one of the more popular functional languages, and the lazy functional language on which the most research is being performed. A225224 and A221646 are from seed 1 and A088204 from seed 3. The I/O system in Haskell is purely functional, yet has all of the expressive power found in conventional programming languages. a guest Mar 30th, 2015 286 Never Not a member of Pastebin yet? The first few numbers are 1, 11, 21, 1211, 111221, 312211 and 13112221. I don't really understand the where clause but that does not work :( permalink That becomes “one two, one one”, or 1211, and so on. The Look and Say sequence. Starting with 1 the sequence would be read out loud as 1 one 1 two 1s one 2 one 1 and so forth and the result is 1 11 21 1211 111221 … . Nth element of Look-And-Say sequence in Haskell. For instance, the term after 1211 is “one 1, one 2, and two 1s”, or 111221. The value of this list lies in being able to look up a textual username for a given UID, not in the order of the data. newSequence newValue oldSequence = Sequence.update 3000 newValue oldSequence will produce a new sequence with a newValue for in the place of its 3000 element. Haskell will look at how you use the variables and figure out from there what type the variable should be - then it will all be type-checked to ensure there are no type-mismatches. the output sequence would be 23211435.1 Thus the resulting sequences are also sometimes called “look and say” sequences. 5 kyu . So: 1) The look-and-say-sequence does not depend much on the chosen base, with one important restriction: Much of the regularity in the behavior relies on the fact that no other number than $1,2,3$ can appear in the sequence. 38 38 11 95% of 143 453 GiacomoSorbi. The sequence is then determined by pairs of digits. The Look and Say sequence is an interesting sequence of numbers where each term is given by describing the makeup of the previous term. The look-and-say sequence (which I talked about here) is the sequence that you get by starting with the number 1 and constructing the next term in the sequence by “reading” the previous term.So 1 becomes “one one”, or 11. The Look and Say sequence starts with 1 and is continued by looking at each of the runs of the same number in the previous element and combining the length with the original number. Because in the world of haskell, a list is a collection of results from a calculation that could be zero, one or several elements. Quick reminder: The sequence starts with 1, Subsequent terms of this sequence are generated by enumerating each group … The value is architecture-dependent, so don’t just Google it—ﬁnd out empiri-cally. Active 2 years, 3 months ago. In imperative languages, programs proceed via actions which examine and modify the current state of the world. 5 kyu. Although Haskell has a comparatively small user community, its strengths have been well applied to a few projects. Embed report print Haskell 0.79 KB numbers generated by describing each number to produce next numbers term look-and-say... Term after 1211 is “ one two, one 2, and indeed they.... Conway on properties he discovered within the so-called look-and-say sequence at first use emacs I recommend installing Intero (:... This post I want to look at this and Say sequence is a functional language on which the research! Map type provided by Data.Map module in look-and-say ( or Count and what. To a few challenges involving the look-and-say sequence is quite ea s y to understand the possible! 23, 12 - > 1,1,1,2 - > 23, 12 - > 1112 - > -... Key into a database to understand terms of even ranks are figures 1, 11,,... 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