.gitignore

@@ -1,15 +1 @@
-# Ignore all executables
-### Ignore all
-*
-### Unignore all with extensions
-!*.*
-### Unignore all dirs
-!*/
-
-
-# Regular gitignore
 .direnv
-
-# Haskell IR files
-*.hi
-*.o

.vscode/settings.json

@@ -2,7 +2,6 @@
   "cSpell.words": [
     "concat",
     "coprime",
-    "elems",
     "foldl"
   ]
 }

flake.nix

@@ -55,18 +55,6 @@
             Chart-cairo
           ]
         );
-
-        clean = pkgs.writeShellScriptBin "clean" ''
-          # Delete executables
-            find . -type f -executable -not -path '*/.git/*' -delete
-
-          # Delete all Haskell IR files
-            find . -type f -name '*.hi' -delete
-            find . -type f -name '*.o' -delete
-
-          # Delete any test graphs created
-            find . -type f -name 'test.png' -delete
-        '';
       in
       pkgs.mkShell {
         buildInputs = with pkgs.haskellPackages; [
@@ -75,9 +63,6 @@
           haskell-language-server
           ghcid
           hlint
-
-          # Scripts
-          clean
         ];
 
         shellHook = ''

src/interviewing.io/2023-09-16-question1.hs

@@ -1,49 +0,0 @@
-import qualified Data.List  as List
-import qualified Data.Maybe as Maybe
-import           Data.Set   (Set)
-import qualified Data.Set   as Set
-
-{-
-interviewing.io question:
-<https://interviewing.io/mocks/linked-in-python-matching-pairs>
-
-Given a list of whole positive numbers, how would you go about finding two numbers in that list that sum up to a given target number. Assume no duplicates in list.
-
--}
-
-
-wholePositiveNumbers :: Set Integer
-wholePositiveNumbers = Set.fromAscList [1..1_000_000]
-
--- findTargetSumIn xs n =
---   (if abs (x-n) `member` xs
---     && abs (x-n) + x == n
---     then Just (abs (x-n), x)
---     else Nothing) : findTargetSumIn xs n
---     where
---       x =
-ans lst sum = List.nubBy isMirror $ Maybe.catMaybes $ Set.elems $ Set.map (\x ->
-    let x' = abs (x-sum)
-    in
-      if x' `Set.member` lst
-      && x' + x == sum
-        then Just (x',x)
-        else Nothing
-  ) lst
-
-isMirror (a,a') (b,b')
-   = a == b'
-  && b == a'
-
-example  = Set.fromList [14,13,6,7,8,10,1,2]
-example' = Set.fromList [14,13,6,7,8,10,1]
-example'' = Set.fromList [1,14,13,3,6,7,2,8,10,4]
-
-main = do
-  print "Quick 3 answers:"
-  print $ ans example 3
-  print $ ans example' 3
-  print $ ans example'' 5
-
-  print "Long answer"
-  print $ ans wholePositiveNumbers 3

src/projectEuler/question13.hs

@@ -221,6 +221,4 @@ ans :: [Integer]
 ans = take 10 $ reverse . digits $ sum oneHundredFiftyDigitNumbers
 
 main :: IO ()
-main = do
-  print ans
-  print (sum oneHundredFiftyDigitNumbers)
+main = print ans

src/projectEuler/question5.hs

@@ -63,5 +63,3 @@ test = map (filter . multipleOf) [1..10]
 
 -- lol
 solve = foldl1 lcm [1..20]
-
-main = print solve

src/projectEuler/question6.hs

@@ -13,29 +13,16 @@ Find the difference between the sum of the squares
   of the first one hundred natural numbers
   and the square of the sum.
 -}
-upperRange :: Integer
-upperRange = 1_000_000
-
-square :: Num a => a -> a
+upperRange = 100
 square n = n^2
-
-squares :: [Integer]
 squares = map square [1..upperRange]
-
-sum' :: [Integer] -> Integer
 sum' = go 0
   where
     go acc []     = acc
     go acc (x:xs) = go (acc+x) xs
 
-sumOfSquares :: Integer
-sumOfSquares = sum squares
+sumOfSquares = sum' squares
 
-squareOfTheSum :: Integer
-squareOfTheSum = sum [1..upperRange] ^2
+squareOfTheSum = (sum [1..upperRange])^2
 
-solution :: Integer
 solution = squareOfTheSum - sumOfSquares
-
-main :: IO ()
-main = print solution

src/projectEuler/question7.hs

@@ -1,9 +1,6 @@
 -- https://projecteuler.net/problem=7
 -- Find the 10_001 prime number
 
--- import           Data.Numbers.Primes (primes)
-import           Math.NumberTheory.Primes (primes)
-
 primes1 :: [Integer]
 primes1 = 2:3:prs
   where
@@ -33,8 +30,3 @@ primes2 = 2:([3..] `minus` composites)
 primes3 = sieve [2..]
   where
     sieve (p : xs) = p : sieve [x | x <- xs, x `mod` p > 0]
-
-main :: IO ()
-main = print $ "Arithmoi - Math.NumberTheory.Primes: " <> show ans
-
-ans = primes !! 10_000_000

src/projectEuler/question8.hs

@@ -28,7 +28,6 @@ What is the value of this product?
 module Main where
 
 import           Data.Char       (ord)
-import           Data.Foldable   (maximumBy)
 import           Data.List       (sort)
 import           Data.List.Split (splitOn)
 
@@ -47,16 +46,9 @@ digits = go []
 main :: IO ()
 main = print ans
 
-ans :: ([Integer], Integer)
-ans = (l, p)
-  where
-    l = maximumBy c $ (windowsOf 13 . digits) thousandDigitNum
-    p = product l
-    c a b
-      | product a > product b = GT
-      | product a < product b = LT
-      | otherwise = EQ
--- "([5,5,7,6,6,8,9,6,6,4,8,9,5],23514624000)"
+ans :: [[Integer]]
+ans = (windowsOf 13 . digits) thousandDigitNum
+-- "9878799272442"
 
 -- what dose it mean to have the greatest product in adjacent digits?
 --  why ask it like that???

src/projectEuler/question9.hs

@@ -17,39 +17,14 @@ Find the product `abc`.
 -}
 
 main :: IO ()
-main = do
-  print answer
-  print (product answer)
+main = print answer
 
--- head $ [(a,b,c) | a <- [1..limit], b <- [a+1..limit], c <- [limit - a - b], a < b, b < c, a^2 + b^2 == c^2]
-answer :: [Integer]
-answer = head $
-  [ [a, b, c] |
-    a <- [1 .. limit],
-    b <- [a + 1 .. limit],
-    c <- [limit - a - b],
-    b < c,
-    a ^ 2 + b ^ 2 == c ^ 2]
-  where limit = 1000
-
-limit = 1000
-version1 =   [ [a, b, c] |
-    a <- [1 .. limit],
-    b <- [a + 1 .. limit],
-    c <- [limit - a - b],
-    b < c,
-    a ^ 2 + b ^ 2 == c ^ 2]
-
-version2 =   [ [a, b, c] |
-    a <- [1 .. limit],
-    b <- [a + 1 .. limit],
-    c <- [limit - a - b],
-    b < c,
-    a ^ 2 + b ^ 2 == c ^ 2]
+answer :: String
+answer = "I dunno"
 
 
 solve :: Integer -> [(Integer, Integer, Integer)]
-solve x = takeWhile (\(a,b,c) -> a + b + c == 1000) $ primitiveTriplesUnder x
+solve x = takeWhile (\(a,b,c) -> a + b + c <= 1000) $ primitiveTriplesUnder x
 
 euclid'sFormula :: Num c => (c, c) -> (c, c, c)
 euclid'sFormula (m, n) = (a,b,c)
@@ -112,19 +87,19 @@ ans' limit = [(a, b, c)
               , b < c
              ]
 
-{-
+{- 
  - Solution to Project Euler problem 9
  - Copyright (c) Project Nayuki. All rights reserved.
- -
+ - 
  - https://www.nayuki.io/page/project-euler-solutions
  - https://github.com/nayuki/Project-Euler-solutions
  -}
 
 
--- -- Computers are fast, so we can implement a brute-force search to directly solve the problem.
--- perim = 1000
--- main = putStrLn (show ans)
--- ans = head [a * b * (perim - a - b) | a <- [1..perim], b <- [a+1..perim], isIntegerRightTriangle a b]
--- isIntegerRightTriangle a b = a < b && b < c
--- 	&& a * a + b * b == c * c
--- 	where c = perim - a - b
+-- Computers are fast, so we can implement a brute-force search to directly solve the problem.
+perim = 1000
+main = putStrLn (show ans)
+ans = head [a * b * (perim - a - b) | a <- [1..perim], b <- [a+1..perim], isIntegerRightTriangle a b]
+isIntegerRightTriangle a b = a < b && b < c
+	&& a * a + b * b == c * c
+	where c = perim - a - b