From bcdb137846c8c492fb895b7dc011b1fa06c85b2d Mon Sep 17 00:00:00 2001 From: Vidir Valberg Gudmundsson Date: Mon, 4 Dec 2017 21:44:43 +0100 Subject: [PATCH] 1st of December - first OCaml program --- dec1.ml | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 dec1.ml diff --git a/dec1.ml b/dec1.ml new file mode 100644 index 0000000..4f70268 --- /dev/null +++ b/dec1.ml @@ -0,0 +1,47 @@ +(*The captcha requires you to review a sequence of digits (your puzzle input) and*) +(*find the sum of all digits that match the next digit in the list. The list is*) +(*circular, so the digit after the last digit is the first digit in the list.*) + +(*For example:*) + (*1122 produces a sum of 3 (1 + 2) because the first digit (1) matches the*) + (*second digit and the third digit (2) matches the fourth digit.*) + (*1111 produces 4 because each digit (all 1) matches the next.*) + (*1234 produces 0 because no digit matches the next.*) + (*91212129 produces 9 because the only digit that matches the next one is the*) + (*last digit, 9.*) + +open Core + +let char_to_int x = int_of_string (Char.to_string x) + +let rec algo' (chars : char list) (first : int) (acc : int list) = + match chars with + | [] -> List.fold_left ~f:(+) ~init:0 acc + | c1 :: (c2 :: rest) -> + if Char.equal c1 c2 + then algo' (c2 :: rest) first (char_to_int c1 :: acc) + else algo' (c2 :: rest) first acc + | c1 :: [] -> + if char_to_int c1 = first + then algo' [] first (first :: acc) + else algo' [] first acc + + +let algo (chars : char list) = + let + first = match List.hd chars with + | Some x -> x + | None -> '0' + in + algo' chars (char_to_int first) [] + + +let solve_captcha number = + number + |> String.to_list + |> algo + |> printf "Passcode is: %d\n" + + +let () = + solve_captcha "57276274387944537823652626177853384411146325384494935924454336611953119173638191671326254832624841593421667683474349154668177743437745965461678636631863541462893547616877914914662358836365421198516263335926544716331814125295712581158399321372683742773423626286669759415959391374744214595682795818615532673877868424196926497731144319736445141728123322962547288572434564178492753681842244888368542423832228211172842456231275738182764232265933625119312598161192193214898949267765417468348935134618964683127194391796165368145548814473129857697989322621368744725685183346825333247866734735894493395218781464346951777873929898961358796274889826894529599645442657423438562423853247543621565468819799931598754753467593832328147439341586125262733737128386961596394728159719292787597426898945198788211417854662948358422729471312456437778978749753927251431677533575752312447488337156956217451965643454445329758327129966657189332824969141448538681979632611199385896965946849725421978137753366252459914913637858783146735469758716752765718189175583956476935185985918536318424248425426398158278111751711911227818826766177996223718837428972784328925743869885232266127727865267881592395643836999244218345184474613129823933659422223685422732186536199153988717455568523781673393698356967355875123554797755491181791593156433735591529495984256519631187849654633243225118132152549712643273819314433877592644693826861523243946998615722951182474773173215527598949553185313259992227879964482121769617218685394776778423378182462422788277997523913176326468957342296368178321958626168785578977414537368686438348124283789748775163821457641135163495649331144436157836647912852483177542224864952271874645274572426458614384917923623627532487625396914111582754953944965462576624728896917137599778828769958626788685374749661741223741834844643725486925886933118382649581481351844943368484853956759877215252766294896496444835264357169642341291412768946589781812493421379575569593678354241223363739129813633236996588711791919421574583924743119867622229659211793468744163297478952475933163259769578345894367855534294493613767564497137369969315192443795512585"