part1

-module(part1).
-export([pass_candy/4]).

%% Pass candy until all students have equal values
pass_candy(Turn, S1, S2, S3) ->
    case check(S1,S2,S3) of
        %% If they all have equal candy print the result
        true ->
            io:format("Turn:~B ",[Turn]),
            io:format("S1:~B ",[S1]),
            io:format("S2:~B ",[S2]),
            io:format("S3:~B~n",[S3]);
        %% If not, pass candy around according the rules
        false ->
            pass_candy(Turn+1, adjust(S3,S1), adjust(S1,S2), adjust(S2,S3))
    end.

%% Adjust the candy
adjust(Pas, Rec) ->
    %% Passer gives half of their candy
    Give = Pas div 2,
    %% Receiver is reduced by half because they need to give
    Temp = (Rec div 2) + Give,
    %% If the end result is odd, add 1
    case Temp rem 2 of
        0 ->
            Temp;
        1 ->
            Temp+1
    end.

%% Check if they are all equal
check(S1, S2, S3) ->
    (S1==S2) andalso (S2==S3).