Singly-linked list/Reversal: Difference between revisions
Added Algol 68
(Created page with "{{draft task}} :I don't even know how to reverse a linked-list, and I don't even know what that is. -- a YouTuber. Reverse a linked list. Obviously you can do it by turning it into a normal list and back, but feel free to use a smarter, possibly more efficient way.") |
(Added Algol 68) |
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Reverse a linked list. Obviously you can do it by turning it into a normal list and back, but feel free to use a smarter, possibly more efficient way.
=={{header|ALGOL 68}}==
Using the code from the [[Singly-linked list/Traversal#ALGOL_68]] Task
<syntaxhighlight lang="algol68">
BEGIN
MODE STRINGLIST = STRUCT(STRING value, REF STRINGLIST next);
# construct a STRINGLIST wuth a few elments #
STRINGLIST list := ("Big",
LOC STRINGLIST := ("fjords",
LOC STRINGLIST := ("vex",
LOC STRINGLIST := ("quick",
LOC STRINGLIST := ("waltz",
LOC STRINGLIST := ("nymph",NIL))))));
# print the list and buuild the reverse list #
REF STRINGLIST node := list;
REF STRINGLIST reverse := REF STRINGLIST(NIL);
WHILE node ISNT REF STRINGLIST(NIL) DO
reverse := HEAP STRINGLIST
:= STRINGLIST( value OF node, reverse );
print((value OF node, space));
node := next OF node
OD;
print(newline);
# print the reverse list #
node := reverse;
WHILE node ISNT REF STRINGLIST(NIL) DO
print((value OF node, space));
node := next OF node
OD;
print(newline)
END
</syntaxhighlight>
{{out}}
<pre>
Big fjords vex quick waltz nymph
nymph waltz quick vex fjords Big
</pre>
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