From 9c1bb671e72d284dfd2b189bdd884dd2f824169b Mon Sep 17 00:00:00 2001 From: Aleksander Sadikov Date: Mon, 14 Mar 2016 18:15:09 +0100 Subject: Hints and plans for permute/2 added. --- prolog/problems/lists/permute_2/common.py | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) (limited to 'prolog/problems/lists/permute_2/common.py') diff --git a/prolog/problems/lists/permute_2/common.py b/prolog/problems/lists/permute_2/common.py index 3035159..55c2b48 100644 --- a/prolog/problems/lists/permute_2/common.py +++ b/prolog/problems/lists/permute_2/common.py @@ -30,7 +30,6 @@ hint_type = { 'recursive_case': Hint('recursive_case'), 'timeout': Hint('timeout'), 'base_case_arbitrary': Hint('base_case_arbitrary'), - 'second_base_case_missing': Hint('second_base_case_missing'), 'unsuccessful_conc_use': Hint('unsuccessful_conc_use'), 'forcing_result_onto_recursion': Hint('forcing_result_onto_recursion'), } @@ -85,26 +84,17 @@ def hint(code, aux_code): # forcing result onto recursion; case of divide(T, [H1|L1], [H2|L2]) - if not prolog.engine.ask_truthTO(engine_id, 'divide([a,b,c], _, _)') and \ + if not prolog.engine.ask_truthTO(engine_id, 'permute([a,b,c], _)') and \ prolog.engine.ask_truthTO(engine_id, - 'asserta( divide([cob], [yowza,cob], [brix]) ), divide([yowza,brix,cob], [cob], []), retract( divide([cob], [yowza,cob], [brix]) )'): + 'asserta( permute([cob], [yowza,cob]) ), permute([yowza,cob], [cob]), retract( permute([cob], [yowza,cob]) )'): return [{'id': 'forcing_result_onto_recursion'}] # base case succeeds with arbitrary result - if prolog.engine.ask_truthTO(engine_id, 'divide([], L1, L2), (var(L1) ; var(L2))') or \ - prolog.engine.ask_truthTO(engine_id, 'divide([q], L1, L2), (var(L1) ; var(L2))') or \ - prolog.engine.ask_truthTO(engine_id, 'divide([q], [q|L1], L2), (var(L1) ; var(L2))'): + if prolog.engine.ask_truthTO(engine_id, 'permute([], P), var(P)'): return [{'id': 'base_case_arbitrary'}] - # one base case ok, the other one is missing (or bad) - # only trigger when recursion also works, because that makes more sense to the student - # than immediately telling him or her that there is another base case missing - if prolog.engine.ask_truthTO(engine_id, - 'divide([a,b], [a], [b]), \+ divide([a,b,c], [a,c], [b]) ; \+ divide([a,b], [a], [b]), divide([a,b,c], [a,c], [b])'): - return [{'id': 'second_base_case_missing'}] - # missing/failed base case - if not prolog.engine.ask_truth(engine_id, 'divide([], [], [])'): + if not prolog.engine.ask_truth(engine_id, 'permute([], [])'): return [{'id': 'base_case'}] # # target predicate seems to always be false @@ -114,7 +104,7 @@ def hint(code, aux_code): # base cases work, the recursive doesn't (but it doesn't timeout) # this may be left as the last, most generic hint - if not prolog.engine.ask_truth(engine_id, 'divide([qa,qb,qc,qd], [qa,qc], [qb,qd])'): + if not prolog.engine.ask_truth(engine_id, 'permute([qa,qb], [qb,qa])'): return [{'id': 'recursive_case'}] except socket.timeout as ex: -- cgit v1.2.1