Longest common suffix: Difference between revisions
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;Task:
The goal is to write a function to find the longest common suffix string amongst an array of strings.
=={{header|Delphi}}==
{{libheader| System.SysUtils}}
{{libheader| Types}}
{{Trans|Ring}}
<lang Delphi>
program Longest_common_suffix;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
Types;
type
TStringDynArrayHelper = record helper for TStringDynArray
private
class function Compare(const s: string; a: TStringDynArray; subSize: integer):
Boolean;
public
function Reverse(value: string): string;
function LongestSuffix: string;
function Join(const sep: char): string;
end;
{ TStringDynArrayHelper }
class function TStringDynArrayHelper.Compare(const s: string; a: TStringDynArray;
subSize: integer): Boolean;
var
i: Integer;
begin
for i := 0 to High(a) do
if s <> a[i].Substring(0, subSize) then
exit(False);
Result := True;
end;
function TStringDynArrayHelper.Join(const sep: char): string;
begin
Result := string.Join(sep, self);
end;
function TStringDynArrayHelper.LongestSuffix: string;
var
ALength: Integer;
i, lenMin, longest: Integer;
ref: string;
begin
ALength := Length(self);
// Empty list
if ALength = 0 then
exit('');
lenMin := MaxInt;
for i := 0 to ALength - 1 do
begin
// One string is empty
if self[i].IsEmpty then
exit('');
self[i] := Reverse(self[i]);
// Get the minimum length of string
if lenMin > self[i].Length then
lenMin := self[i].Length;
end;
longest := -1;
repeat
inc(longest);
ref := self[0].Substring(0, longest + 1);
until not compare(ref, Self, longest + 1) or (longest >= lenMin);
Result := self[0].Substring(0, longest);
Result := reverse(Result);
end;
function TStringDynArrayHelper.Reverse(value: string): string;
var
ALength: Integer;
i: Integer;
c: Char;
begin
ALength := value.Length;
Result := value;
if ALength < 2 then
exit;
for i := 1 to ALength div 2 do
begin
c := Result[i];
Result[i] := Result[ALength - i + 1];
Result[ALength - i + 1] := c;
end;
end;
var
List: TStringDynArray;
begin
List := ['baabababc', 'baabc', 'bbbabc'];
Writeln('Input:');
Writeln(List.Join(#10), #10);
Writeln('Longest common suffix = ', List.LongestSuffix);
Readln;
end.
</lang>
{{out}}
<pre>
Input:
baabababc
baabc
bbbabc
Longest common suffix = abc
</pre>
=={{header|Factor}}==
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