Live coding Advent of Code 2015 (first 10 puzzles, OCaml, F#, Haskell and Python)

Some friends and family have gone back to Advent of Code 2015 for practice. I decided to join in on the fun!

0:00 Intro
0:37 Day 1, Part 1 in OCaml
6:20 Day 1, Part 2 in OCaml
12:39 Day 2, Part 1 in F#
20:00 Day 2, Part 2 in F#
24:19 Day 3, Part 1 in Haskell
33:23 Day 3, Part 2 in Haskell
39:27 Day 4, Part 1 in Python
46:48 Day 4, Part 2 in Python
48:05 Day 5, Part 1 in F#
1:02:33 Day 5, Part 2 in F#
1:15:37 Day 6, Part 1 in Python
1:33:25 Day 6, Part 2 in Python
1:36:51 Day 7, Part 1 in Haskell
1:47:12 Day 7, Part 2 in Haskell
1:49:25 Day 8, Part 1 in F#
1:59:41 Day 8, Part 2 in F#
2:04:33 Day 9, Part 1 in Python
2:29:52 Day 9, Part 2 in Python
2:30:55 Day 10, Part 1 in Haskell
2:40:00 Day 10, Part 2 in Haskell
2:41:15 Day 11, Unfinished (had to leave) in Python

[rastislavsvoboda]

appreciate your videos! looking forward to other days! great!!

[rastislavsvoboda]

Hi
for D9 I've iterated over permutations(cities, len(cities))
and computed the distance of all possible paths
then get min/max

[rastislavsvoboda]

Hi
I did D10 in F# (at 2:30:50)
not sure it there is some kind of group like you used in Haskell
but I've did this



let lookAndSay nums =

        match nums with




|> List.rev

let solve limit input =
    [ 1 .. limit ]

    |> List.length

[rastislavsvoboda]

Hi Michael
I think in D5p2 isReallyNice function is not correct
maybe you got lucky and it counts good for your input
but I believe it is wrong for lines when there are 4 same chars in row
I have function

let isNice2' (line: string) =
let hasDoubles =
let mutable res = false

for i in 0 .. line.Length - 2 do
let pair = line.Substring(i, 2)
let newLine = line.ToCharArray()
newLine.[i] <- ' '
newLine.[i + 1] <- ' '
let s = new string (newLine)
if s.Contains pair then res <- true

res

hasDoubles
&& hasRepeatWithBetween (line |> Seq.toList)

I'm not that good at F#
what I do here is that for any consecutive 2 chars
I replace it with 2 spaces at that position
and trying to find if the same 2 chars are still in the string
I've used some idea from my original python version when I first time solved D5

def is_nice(word):

hasDoublePair = False
hasRepeat = False
wordLen = len(word)
for i, s in enumerate(word):
if i < wordLen - 1:
searchPair = word[i:i+2]
newW = word[:i] + " " + word[i+2:]
hasDoublePair |= searchPair in newW

if i < wordLen - 2:
hasRepeat |= word[i] == word[i+2]

if hasDoublePair and hasRepeat:
return True

return False

and I did not know how to better translate it to F# (for the doublePair stuff)

when I compared your and my func, I got these different answers
[(false, true, "xilodxfuxphuiiii"); (false, true, "pzkkkkwrlvxiuysn"); (false, true, "bkkkkcwegvypbrio")]