alan day5 and day6

day5/day5.erl

@@ -0,0 +1,110 @@
+%% to compile: erlc day3A.erl
+%% to run: erl -noshell -s day5 solve
+%%
+-module(day5).
+
+-export ([solve/0, solve/1, solve/2]).
+-export ([read_input/0]).
+
+solve() ->
+    solve(['1']),
+    solve(['2']),
+    init:stop().
+
+solve(A) ->
+    solve(A, read_input()).
+
+solve(['1'], D) ->
+    io:format("The solution to ~p puzzle1 is: ~p~n", [?MODULE, solve(1, D)]);
+solve(1, D) ->
+    solution1(D);
+solve(['2'], D) ->
+    io:format("The solution to ~p puzzle2 is: ~p~n", [?MODULE, solve(2, D)]);
+solve(2, D) ->
+    solution2(D).
+
+read_input() ->
+    {ok, IO} = file:open("input.txt", 'read'),
+    Data = read_input(IO),
+    file:close(IO),
+    Data.
+
+read_input(IO) ->
+	read_input(IO, []).
+
+read_input(IO, Input) ->
+    case read_line(IO) of
+	'eof' ->
+              lists:map(fun([{X1,Y1},{X2,Y2}]) ->
+              case X1 > X2 orelse (X1 == X2 andalso Y1 > Y2) of
+                      'true' ->  [{X2,Y2},{X1,Y1}];
+                      'false' -> [{X1,Y1},{X2,Y2}]
+              end
+              end, Input);
+	Line -> read_input(IO, Input ++ [Line])
+    end.
+
+read_line(IO) ->
+	case file:read_line(IO) of
+		'eof' -> 'eof';
+		{ok, Line} -> parse_line(Line)
+	end.
+
+parse_line(Line) ->
+    Points = string:tokens(Line, " ,->\n"),
+    [X1, Y1, X2, Y2] = [list_to_integer(X) || X <- Points],
+    [{X1, Y1},{X2,Y2}].
+
+solution1(Input) ->
+   HV = get_hor_vert(Input),
+   Points = lists:sort(
+	      lists:flatten(
+		[[{X,Y} || X <- lists:seq(X1, X2, case X1 =< X2 of 'true' -> 1; _ -> -1 end),
+			   Y <- lists:seq(Y1, Y2, case Y1 =< Y2 of 'true' -> 1; _ -> -1 end)] || [{X1,Y1},{X2,Y2}] <- HV]
+	       )
+	     ),
+   Count = count_duplicates(Points),
+   Count.
+
+solution2(Input) ->
+   Points = get_all_points(Input),
+   Count = count_duplicates(lists:sort(Points)),
+   Count.
+
+
+get_hor_vert(Input) ->
+    lists:filter(fun([{X1, Y1},{X2,Y2}]) -> X1 == X2 orelse Y1 == Y2 end, Input).
+
+get_all_points(Input) ->
+    get_all_points(Input, []).
+
+get_all_points([], Acc) -> 
+	Acc;
+get_all_points([[{X1,Y1},{X2,Y2}]|Rest], Acc) when X1 ==  X2 ->
+	get_all_points(Rest, Acc ++ [{X1, Y} ||  Y <- lists:seq(Y1,Y2)]);
+get_all_points([[{X1,Y1},{X2,Y2}]|Rest], Acc) when Y1 ==  Y2 ->
+	get_all_points(Rest, Acc ++ [{X, Y1} ||  X <- lists:seq(X1,X2)]);
+get_all_points([[{X1,Y1},{X2,Y2}]|Rest], Acc) when Y1 < Y2 ->
+	get_all_points(Rest, Acc ++ [{X, Y1-X1+X} ||  X <- lists:seq(X1,X2)]);
+get_all_points([[{X1,Y1},{X2,Y2}]|Rest], Acc) when Y1 > Y2 ->
+	get_all_points(Rest, Acc ++ [{X, (-1 *  X) + X1 + Y1 } ||  X <- lists:seq(X1,X2)]).
+
+count_duplicates(Points) ->
+	count_duplicates(Points, []).
+
+count_duplicates([], Count) -> 
+	lists:foldl(fun({X, _P}, Acc) ->
+		  case X > 1 of 'true' -> Acc + 1; _ -> Acc  end end, 0, Count);
+count_duplicates([H|T], Count) ->
+	case T /= [] andalso hd(T) == H of
+             'true' ->  count_duplicate(H, T, Count, 1);
+             _Else -> count_duplicates(T, Count ++ [{1, H}])
+        end.
+
+count_duplicate(H, [H|T], Count, X) ->
+    count_duplicate(H, T, Count, X + 1);
+count_duplicate(H, List, Count, X) ->
+	count_duplicates(List, Count ++ [{X, H}]).
+
+
+