Anonymous user
Determine if a string has all unique characters: Difference between revisions
Determine if a string has all unique characters (view source)
Revision as of 23:07, 6 January 2020
, 4 years agoAdded Prolog
(Added Prolog) |
|||
Line 1,555:
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (length 36): first duplicate character "0"(#30) at positions 10 and 25
</pre>
=={{header|Prolog}}==
<lang prolog>report_duplicates(S) :-
duplicates(S, Dups),
format('For value "~w":~n', S),
report(Dups),
nl.
report(Dups) :-
maplist(only_one_position, Dups),
format(' All characters are unique~n').
report(Dups) :-
exclude(only_one_position, Dups, [c(Char,Positions)|_]),
reverse(Positions, PosInOrder),
atomic_list_concat(PosInOrder, ', ', PosAsList),
format(' The character ~w is non unique at ~p~n', [Char, PosAsList]).
only_one_position(c(_,[_])).
duplicates(S, Count) :-
atom_chars(S, Chars),
char_count(Chars, 0, [], Count).
char_count([], _, C, C).
char_count([C|T], Index, Counted, Result) :-
select(c(C,Positions), Counted, MoreCounted),
succ(Index, Index1),
char_count(T, Index1, [c(C,[Index|Positions])|MoreCounted], Result).
char_count([C|T], Index, Counted, Result) :-
\+ member(c(C,_), Counted),
succ(Index, Index1),
char_count(T, Index1, [c(C,[Index])|Counted], Result).
test :- report_duplicates('').
test :- report_duplicates('.').
test :- report_duplicates('abcABC').
test :- report_duplicates('XYZ ZYX').
test :- report_duplicates('1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ').</lang>
{{out}}
<pre>
?- forall(test, true).
For value "":
All characters are unique
For value ".":
All characters are unique
For value "abcABC":
All characters are unique
For value "XYZ ZYX":
The character X is non unique at '0, 6'
For value "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ":
The character 0 is non unique at '9, 24'
true.
?-</pre>
=={{header|Python}}==
| |||