PR#3: [wip] Add fbo answers for homework 1 - cis194

cis194

#3 [wip] Add fbo answers for homework 1

Opened 4 years ago by fbo. Modified 4 years ago

fbo/cis194 fbo-homework1 into master

Provided ex4 and started ex5

Fabien Boucher • 4 years ago

716fdf2

Add ex3

Fabien Boucher • 4 years ago

558ee32

[wip] Add fbo answers for homework 1

Fabien Boucher • 4 years ago

d241df3

assignments/fbo/hm1/ex1.hs

file added

+11

		`@@ -0,0 +1,11 @@`
		`+ toDigits :: Integer -> [Integer]`
		`+ toDigits r`
		`+ \| r <= 0 = []`
		`+ \| otherwise = toDigits (div r 10) ++ [mod r 10]`
		`+`
		`+ toDigitsRev :: Integer -> [Integer]`
		`+ toDigitsRev r`
		`+ \| r <= 0 = []`
		`+ \| otherwise = (mod r 10) : toDigitsRev (div r 10)`
		`+`
		`+ main = print (toDigits (-17))`
tdecacqu commented 4 years ago nicely done!

assignments/fbo/hm1/ex2.hs

file added

		`@@ -0,0 +1,9 @@`
		`+ doubleEveryOtherLR :: [Integer] -> [Integer]`
		`+ doubleEveryOtherLR [] = []`
		`+ doubleEveryOtherLR (x:[]) = [x]`
		`+ doubleEveryOtherLR (x:y:zs) = x : y*2 : doubleEveryOtherLR zs`
		`+`
		`+ doubleEveryOther :: [Integer] -> [Integer]`
		`+ doubleEveryOther zs = reverse (doubleEveryOtherLR (reverse zs))`
		`+`
		`+ main = print (doubleEveryOther [10, 9, 8, 7])`

assignments/fbo/hm1/ex3.hs

file added

		`@@ -0,0 +1,9 @@`
		`+ intToList :: Integer -> [Integer]`
		`+ intToList 0 = []`
		`+ intToList x = (mod x 10) : (intToList (div x 10))`
		`+`
		`+ sumDigits :: [Integer] -> Integer`
		`+ sumDigits [] = 0`
		`+ sumDigits (x:xs) = sum(intToList x) + sumDigits xs`
		`+`
		`+ main = print (sumDigits [12, 4])`

assignments/fbo/hm1/ex4.hs

file added

+31

		`@@ -0,0 +1,31 @@`
		`+ toDigits :: Integer -> [Integer]`
		`+ toDigits r`
		`+ \| r <= 0 = []`
		`+ \| otherwise = toDigits (div r 10) ++ [mod r 10]`
		`+`
		`+ doubleEveryOtherLR :: [Integer] -> [Integer]`
		`+ doubleEveryOtherLR [] = []`
		`+ doubleEveryOtherLR (x:[]) = [x]`
		`+ doubleEveryOtherLR (x:y:zs) = x : y*2 : doubleEveryOtherLR zs`
		`+`
		`+ doubleEveryOther :: [Integer] -> [Integer]`
		`+ doubleEveryOther zs = reverse (doubleEveryOtherLR (reverse zs))`
		`+`
		`+ intToList :: Integer -> [Integer]`
		`+ intToList 0 = []`
		`+ intToList x = (mod x 10) : (intToList (div x 10))`
		`+`
		`+ sumDigits :: [Integer] -> Integer`
		`+ sumDigits [] = 0`
		`+ sumDigits (x:xs) = sum(intToList x) + sumDigits xs`
		`+`
		`+ validate :: Integer -> Bool`
		`+ validate x =`
		`+ if mod (`
		`+ sumDigits (`
		`+ doubleEveryOther (toDigits x))) 10 == 0`
		`+ then True`
		`+ else False`
		`+`
tdecacqu commented 4 years ago "if x then True else False" can be written as "x" when x evaluate as a Bool ;) validate x = mod ( sumDigits (doubleEveryOther (toDigits x))) 10 == 0
		`+ main = print (validate 4012888888881881)`
		`+ main = print (validate 4012888888881882)`

assignments/fbo/hm1/ex5.hs

file added

+12

		`@@ -0,0 +1,12 @@`
		`+ type Peg = String`
		`+ type Move = (Peg, Peg)`
		`+ hanoi :: Integer -> Peg -> Peg -> Peg -> [Move]`
		`+ hanoi n a b c`
		`+ \| n == 1 = [(a, c) :: Move]`
		`+`
		`+ a = "A" :: Peg`
		`+ b = "B" :: Peg`
		`+ c = "C" :: Peg`
		`+`
tdecacqu commented 4 years ago "type x = y" actually just creates an alias for "y" named "x". Thus Peg is a String, and "a" is already a String. That means you can call (hanois 1 "a" "b" "c") directly.
		`+ main = print (hanoi 1 a b c)`
		`+ -- TBC`

no initial comment

fbo commented 4 years ago

Build failed.

haskell-lint : FAILURE in 1m 04s

tdecacqu commented on line 12 of assignments/fbo/hm1/ex1.hs 4 years ago

nicely done!

1 new commit added

Add ex3

4 years ago

fbo commented 4 years ago

Build failed.

haskell-lint : FAILURE in 1m 10s

1 new commit added

Provided ex4 and started ex5

4 years ago

fbo commented 4 years ago

Build failed.

haskell-lint : FAILURE in 1m 35s

tdecacqu commented on line 30 of assignments/fbo/hm1/ex4.hs 4 years ago

"if x then True else False" can be written as "x" when x evaluate as a Bool ;)

validate x = mod ( sumDigits (doubleEveryOther (toDigits x))) 10 == 0

tdecacqu commented on line 11 of assignments/fbo/hm1/ex5.hs 4 years ago

"type x = y" actually just creates an alias for "y" named "x". Thus Peg is a String, and "a" is already a String. That means you can call (hanois 1 "a" "b" "c") directly.