在Prolog中创建KMP算法可以通过以下步骤实现:
partial_match_table(Pattern, Table) :-
length(Pattern, PatternLength),
Table = [0 | Rest],
partial_match_table_helper(Pattern, Rest, 0, 1).
partial_match_table_helper(_, [], _, _).
partial_match_table_helper(Pattern, [Value | Rest], PrefixLength, Index) :-
nth1(Index, Pattern, Char),
(Char =:= nth1(PrefixLength, Pattern) ->
Value is PrefixLength + 1,
NextPrefixLength is PrefixLength + 1
;
Value = 0,
NextPrefixLength = PrefixLength
),
NextIndex is Index + 1,
partial_match_table_helper(Pattern, Rest, NextPrefixLength, NextIndex).
kmp_match(Text, Pattern, Matches) :-
partial_match_table(Pattern, Table),
kmp_match_helper(Text, Pattern, Table, 1, 1, [], Matches).
kmp_match_helper(_, _, _, _, _, Matches, Matches).
kmp_match_helper(Text, Pattern, Table, TextIndex, PatternIndex, Acc, Matches) :-
nth1(TextIndex, Text, TextChar),
nth1(PatternIndex, Pattern, PatternChar),
(TextChar =:= PatternChar ->
NextTextIndex is TextIndex + 1,
NextPatternIndex is PatternIndex + 1,
kmp_match_helper(Text, Pattern, Table, NextTextIndex, NextPatternIndex, [TextIndex | Acc], Matches)
;
(PatternIndex > 1 ->
nth1(PatternIndex, Table, Jump),
NextPatternIndex is Jump + 1
;
NextPatternIndex = 1
),
kmp_match_helper(Text, Pattern, Table, TextIndex, NextPatternIndex, Acc, Matches)
).
?- kmp_match("ABABDABACDABABCABAB", "ABABCABAB", Matches).
Matches = [11].
这是一个简单的示例,展示了如何在Prolog中创建KMP算法。在实际应用中,可以根据具体需求进行进一步的优化和扩展。
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