36 lines
953 B
OCaml
36 lines
953 B
OCaml
#use "lib/utils.ml" ;;
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type pointer = {ring: char List.t; pos: int} ;;
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let find_marker seq width =
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let find_marker' ptr i c =
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if ptr.pos > 0 then ptr
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else
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let rec chars_repeat = function
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| [] -> false
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| hd :: tl -> List.exists ((=) hd) tl || chars_repeat tl
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in
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let ring =
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if List.length ptr.ring = width
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then List.tl ptr.ring @ [c]
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else ptr.ring @ [c]
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in
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let pos =
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if List.length ptr.ring = width && not(chars_repeat ptr.ring)
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then i + 1
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else 0
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in
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{ring = ring; pos = pos}
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in
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let ptr = {ring = []; pos = 0} in
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let ptr = Seq.fold_lefti find_marker' ptr seq in
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ptr.pos
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in
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let contents = read_file "inputs/6.txt" in
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let reader = String.to_seq contents in
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let marker_pos = find_marker reader 4 in
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let message_pos = find_marker reader 14 in
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Printf.printf "Solution 1: %d\n" marker_pos;
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Printf.printf "Solution 2: %d\n" message_pos
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