賢者からの挑戦 竹俣紅女流 Question.3

m.erl

%% egglang <[email protected]>
%%
%% 賢者からの挑戦 http://www.math4life.jp/
%% 竹俣紅 Q3.

-module(m).
-compile(export_all).

main() ->
	beni3(create_matrix(5, 5)).

put_and_print({X,Y}, Val) ->
	put({X,Y}, Val),
    io:format("X: ~p, Y: ~p Value: ~p ~n",[X, Y, Val]).

-spec create_matrix(integer(), integer()) -> list().
create_matrix(XNum, YNum) ->
	Mat = [{X,Y} ||  X <- lists:seq(1, XNum), Y <- lists:seq(1, YNum)],
	[put(T, 0) || T <- Mat], % put initial values into a process dictionary.
	Mat.

-spec beni3(list()) -> integer().
beni3(L) -> beni3(L, 0).

-spec beni3(list(), integer()) -> integer().
beni3([], Val) -> Val;
beni3([{1,1}|T], Val) -> put_and_print({1,1}, 1), beni3(T, Val);
beni3([{2,1}|T], Val) -> put_and_print({2,1}, 1), beni3(T, Val);
beni3([{1,2}|T], Val) -> put_and_print({1,2}, 1), beni3(T, Val);
beni3([{X,Y}|T], _) ->
    MyVal = lists:sum([get({IX,Y}) || IX <- lists:seq(1,X)]) + lists:sum([get({X,IY}) || IY <- lists:seq(1,Y)]),
    put_and_print({X,Y}, MyVal),
    beni3(T, MyVal).

% result:
%
% 1> c(m).
% {ok,m}
% 2> m:main().
% X: 1, Y: 1 Value: 1 
% X: 1, Y: 2 Value: 1 
% X: 1, Y: 3 Value: 2 
% X: 1, Y: 4 Value: 4 
% X: 1, Y: 5 Value: 8 
% X: 2, Y: 1 Value: 1 
% X: 2, Y: 2 Value: 2 
% X: 2, Y: 3 Value: 5 
% X: 2, Y: 4 Value: 12 
% X: 2, Y: 5 Value: 28 
% X: 3, Y: 1 Value: 2 
% X: 3, Y: 2 Value: 5 
% X: 3, Y: 3 Value: 14 
% X: 3, Y: 4 Value: 37 
% X: 3, Y: 5 Value: 94 
% X: 4, Y: 1 Value: 4 
% X: 4, Y: 2 Value: 12 
% X: 4, Y: 3 Value: 37 
% X: 4, Y: 4 Value: 106 
% X: 4, Y: 5 Value: 289 
% X: 5, Y: 1 Value: 8 
% X: 5, Y: 2 Value: 28 
% X: 5, Y: 3 Value: 94 
% X: 5, Y: 4 Value: 289 
% X: 5, Y: 5 Value: 838 
% 838