104 lines
4.8 KiB
Erlang
104 lines
4.8 KiB
Erlang
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-module(day25).
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-export([start/0]).
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part_1()
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-> state_a(maps:new(), 0, 0, 6).
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state_a(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_a(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index + 1,
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state_b(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_a(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 0, Tape),
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NewIndex = Index - 1,
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state_b(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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state_b(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_b(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index - 1,
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state_a(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_b(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index + 1,
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state_a(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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diagnostic_checksum(Tape)
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-> maps:fold(fun(_K, V, Sum) -> Sum + V end, 0, Tape).
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part_2()
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-> state_a2(maps:new(), 0, 0, 12861455).
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state_a2(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_a2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index + 1,
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state_b2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_a2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 0, Tape),
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NewIndex = Index - 1,
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state_b2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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state_b2(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_b2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index - 1,
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state_c2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_b2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 0, Tape),
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NewIndex = Index + 1,
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state_e2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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state_c2(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_c2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index + 1,
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state_e2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_c2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 0, Tape),
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NewIndex = Index - 1,
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state_d2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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state_d2(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_d2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index - 1,
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state_a2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_d2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index - 1,
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state_a2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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state_e2(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_e2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 0, Tape),
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NewIndex = Index + 1,
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state_a2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_e2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 0, Tape),
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NewIndex = Index + 1,
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state_f2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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state_f2(Tape, _Index, _CurrentBit, Steps)
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when Steps == 0 -> Tape;
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state_f2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 0 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index + 1,
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state_e2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1);
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state_f2(Tape, Index, CurrentBit, Steps)
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when CurrentBit == 1 -> NewTape = maps:put(Index, 1, Tape),
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NewIndex = Index + 1,
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state_a2(NewTape, NewIndex, maps:get(NewIndex, NewTape, 0), Steps - 1).
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start()
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-> io:fwrite("sample diagnostic checksum ~p~n", [diagnostic_checksum(part_1())]),
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io:fwrite("problem diagnostic checksum ~p~n", [diagnostic_checksum(part_2())]).
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