53 lines
2.2 KiB
OCaml
53 lines
2.2 KiB
OCaml
open Utils
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let initial_state =
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let ht = Hashtbl.create 12345 in
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let _ = Hashtbl.add ht 1 ["S"; "P"; "H"; "V"; "F"; "G"] in
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let _ = Hashtbl.add ht 2 ["M"; "Z"; "D"; "V"; "B"; "F"; "J"; "G"] in
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let _ = Hashtbl.add ht 3 ["N"; "J"; "L"; "M"; "G"] in
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let _ = Hashtbl.add ht 4 ["P"; "W"; "D"; "V"; "Z"; "G"; "N"] in
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let _ = Hashtbl.add ht 5 ["B"; "C"; "R"; "V"] in
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let _ = Hashtbl.add ht 6 ["Z"; "L"; "W"; "P"; "M"; "S"; "R"; "V"] in
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let _ = Hashtbl.add ht 7 ["P"; "H"; "T"] in
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let _ = Hashtbl.add ht 8 ["V"; "Z"; "H"; "C"; "N"; "S"; "R"; "Q"] in
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let _ = Hashtbl.add ht 9 ["J"; "Q"; "V"; "P"; "G"; "L"; "F"] in
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ht
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exception InvalidMoveLine
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let parse_move line =
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match String.split_on_char ' ' line with
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| "move" :: count :: "from" :: st_from :: "to" :: st_to :: [] ->
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(int_of_string count, int_of_string st_from, int_of_string st_to)
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| _ -> raise InvalidMoveLine
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let move stacks f (count, idx_from, idx_to) =
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let from_stack = Hashtbl.find stacks idx_from in
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let to_stack = Hashtbl.find stacks idx_to in
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let rec aux count res_from append_to =
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if count = 0 then (res_from, append_to)
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else match res_from with
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| h :: t -> aux (count - 1) t (h :: append_to)
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| [] -> (res_from, append_to) in
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let (res_from, res_to) = aux count from_stack [] in
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let _ = Hashtbl.replace stacks idx_from res_from in
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let _ = Hashtbl.replace stacks idx_to (List.append (f res_to) to_stack) in
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stacks ;;
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let parsed_moves = read_file "bin/d5/input.txt"
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|> List.filter_map
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(fun line ->
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try Some(parse_move line)
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with InvalidMoveLine -> let _ = print_endline ("invalid line " ^ line) in None) ;;
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let solve f input =
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let state = Hashtbl.copy initial_state in
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let _ = input
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|> List.map (move state f) in
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let res = Hashtbl.length state
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|> range
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|> List.fold_left (fun acc x -> acc ^ (List.hd (Hashtbl.find state x))) "" in
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print_endline ("\n" ^ res) ;;
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solve id parsed_moves ;;
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solve List.rev parsed_moves ;;
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