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Improved mod in CLP(Z)

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This is still a work in progress.
This commit is contained in:
notoria
2020-08-10 21:00:54 +02:00
parent 8203eff47b
commit a24fbb8f61
1 changed files with 112 additions and 1 deletions
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113
src/lib/clpz.pl
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@@ -4924,7 +4924,7 @@ run_propagator(ptzdiv(X,Y,Z), MState) -->
%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% % Z = X mod Y
run_propagator(pmod(X,Y,Z), MState) -->
run_propagator(pmod_(X,Y,Z), MState) -->
( nonvar(X) ->
( nonvar(Y) -> kill(MState), Y =\= 0, Z is X mod Y
; true
@@ -5016,6 +5016,117 @@ run_propagator(pmod(X,Y,Z), MState) -->
% TODO: propagate more
).
run_propagator(pmod(X,Y,Z), MState) -->
( Y == 0 -> { false }
; Y == Z -> { false }
% ; nonvar(Y), Z == X -> true
; X == Y -> kill(MState), Z = 0
; true
),
( nonvar(X), nonvar(Y) ->
kill(MState),
Z is X mod Y
; nonvar(Y), nonvar(Z) ->
( Y > 0 -> Z >= 0, Z < Y
; Y < 0 -> Z =< 0, Z > Y
)
% kill(MState),
% queue_goal(X #= Z + Y * _) % Add a variable to be efficient.
; nonvar(Z), nonvar(X) ->
( Z > 0 ->
( X < 0 -> true
; X >= Z
)
; Z < 0 ->
( X > 0 -> true
; X =< Z
)
; Z =:= 0 % Multiple solutions so do nothing special.
),
( Z > 0 -> queue_goal(Y #> 0)
; Z < 0 -> queue_goal(Y #< 0)
; true
)
; run_propagator(pmodz(X,Y,Z), MState),
run_propagator(pmody(X,Y,Z), MState),
run_propagator(pmodx(X,Y,Z), MState),
true
).
run_propagator(pmodz(X,Y,Z), MState) -->
( nonvar(Z) -> true % Nothing to do.
; nonvar(X) ->
( X =:= 0 -> kill(MState), Z = X
; X > 0 -> queue_goal(Z #=< X)
; X < 0 -> queue_goal(Z #>= X)
),
( { fd_get(Y, _, n(YL), n(YU), _), YL > 0 } ->
{ ZMax is YU - 1 },
queue_goal(Z in 0..ZMax)
; { fd_get(Y, _, n(YL), n(YU), _), YU < 0 } ->
{ ZMin is YL + 1 },
queue_goal(Z in ZMin..0)
; true
)
; nonvar(Y) ->
( abs(Y) =:= 1 -> kill(MState), Z = 0
; Y < 0 ->
{ ZMin is Y + 1 },
queue_goal(Z in ZMin..0)
; Y > 0 ->
{ ZMax is Y - 1 },
queue_goal(Z in 0..ZMax)
),
( { fd_get(X, _, n(XL), n(XU), _), XL >= 0 } ->
queue_goal(Z #=< XU)
; { fd_get(X, _, n(XL), n(XU), _), XU =< 0 } ->
queue_goal(Z #>= XL)
; true
)
; ( { fd_get(X, _, n(XL), n(XU), _), XL >= 0 } ->
queue_goal(Z #=< XU)
; { fd_get(X, _, n(XL), n(XU), _), XU =< 0 } ->
queue_goal(Z #>= XL)
; true
),
( { fd_get(Y, _, n(YL), n(YU), _), YL > 0 } ->
{ ZMax is YU - 1 },
queue_goal(Z in 0..ZMax)
; { fd_get(Y, _, n(YL), n(YU), _), YU < 0 } ->
{ ZMin is YL + 1 },
queue_goal(Z in ZMin..0)
; true
)
).
run_propagator(pmody(X,Y,Z), MState) -->
( nonvar(Y) -> true % Nothing to do.
% ; nonvar(X) -> true
; nonvar(Z) ->
( Z > 0 -> queue_goal(Y #> Z)
; Z < 0 -> queue_goal(Y #< Z)
; Z =:= 0 -> kill(MState), queue_goal(X / Y #= _)
)
; ( { fd_get(Z, _, n(ZL), _, _), ZL > 0 } ->
queue_goal(Y #> ZL)
; { fd_get(Z, _, _, n(ZU), _), ZU < 0 } ->
queue_goal(Y #< ZU)
; true
)
).
run_propagator(pmodx(X,Y,Z), MState) -->
( nonvar(X) -> true % Nothing to do.
% ; nonvar(Y) -> true
/*
; nonvar(Z) ->
( Z =:= 0 -> kill(MState), queue_goal(X / Y #= _)
; true
)
% */
; true
).
%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% % Z = X rem Y