Skip to main content

Microsoft Azure Notebooks - Live code - F#, R, and Python

I was exploring Jupyter notebooks , that combines live code, markdown and data, through Microsoft's implementation, known as MS Azure Notebooks , putting together a small library of R and F# notebooks . As Microsoft's FAQ for the service describes it as : ...a multi-lingual REPL on steroids. This is a free service that provides Jupyter notebooks along with supporting packages for R, Python and F# as a service. This means you can just login and get going since no installation/setup is necessary. Typical usage includes schools/instruction, giving webinars, learning languages, sharing ideas, etc. Feel free to clone and comment... In R Azure Workbook for R - Memoisation and Vectorization Charting Correlation Matrices in R In F# Charnownes Constant in FSharp.ipynb Project Euler - Problems 18 and 67 - FSharp using Dynamic Programming
Post a Comment

Project Euler - Problem #16

I'm fairly happy with this, since it executes speedily, and builds on prior work solving problems.  It uses a tail-recursive function and BigInteger to find the power, and a fairly straightforward conversion of the number in to a string, which it then sums.


Description

  • 215 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
  • What is the sum of the digits of the number 2^1000?

Solution


//tail-recursive function to sum array of BigInteger
open System.Numerics
let rec productBigInt (num:BigInteger) (power:BigInteger) (max:BigInteger) (acc:BigInteger) =
    if  power = max  then
        acc  * num
    else
        productBigInt num (power + 1I) max (num * acc)


//smaller aspects of function ot solve problem
let prodResult = productBigInt 2I 1I 1000I 1I
let strCharProd = prodResult.ToString()
let lenProd = strCharProd.Length


//main to solve problem
let sumPower = 
    let prodResult = productBigInt 2I 1I 1000I 1I
    let strCharProd = prodResult.ToString()
    let max = strCharProd.Length
    let arrNum = Array.create max 0    
    for i=0 to max-1 do
        arrNum.[i] <- System.Convert.ToInt32(strCharProd.Chars(i).ToString())
    Array.sum arrNum

Comments

Post a Comment

Popular posts from this blog

Project Euler - Problem 17 (Match-based Solution)

Problem If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total. If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how many letters would be used? NOTE: Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of "and" when writing out numbers is in compliance with British usage. Note I have done two (2) solutions for this problem. The original in a prior post requires less code, but is 'ugly' and is less reusable that this match-based solution. This solution is based on smaller methods using the match function, with larger number functions able to call and reuse code from the functions for smaller numbers.  Calling the method is much cleaner as well. Solution ( Match-Based ) let GetThousandthsLetters prefix fourth third second first =...
3 comments
Read more

Digit cancelling fractions (Project Euler Problem 33)

Problem The fraction 49/98 is a curious fraction, as an inexperienced mathematician in attempting to simplify it may incorrectly believe that 49/98 = 4/8, which is correct, is obtained by cancelling the 9s. We shall consider fractions like, 30/50 = 3/5, to be trivial examples. There are exactly four non-trivial examples of this type of fraction, less than one in value, and containing two digits in the numerator and denominator. If the product of these four fractions is given in its lowest common terms, find the value of the denominator. (link to Problem 33 on the Project Euler site) Note This is a somewhat crude solution, since I am only just getting back into solving these problems, or working with F#, but there are several similar problems for which I can develop properly factored, reusable functions. Solution open System let product xs ys = seq{for x in xs do for y in ys do let a = float x % float 10 ...
Post a Comment
Read more

Microsoft Azure Notebooks - Live code - F#, R, and Python

I was exploring Jupyter notebooks , that combines live code, markdown and data, through Microsoft's implementation, known as MS Azure Notebooks , putting together a small library of R and F# notebooks . As Microsoft's FAQ for the service describes it as : ...a multi-lingual REPL on steroids. This is a free service that provides Jupyter notebooks along with supporting packages for R, Python and F# as a service. This means you can just login and get going since no installation/setup is necessary. Typical usage includes schools/instruction, giving webinars, learning languages, sharing ideas, etc. Feel free to clone and comment... In R Azure Workbook for R - Memoisation and Vectorization Charting Correlation Matrices in R In F# Charnownes Constant in FSharp.ipynb Project Euler - Problems 18 and 67 - FSharp using Dynamic Programming
Post a Comment
Read more