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// Generic types for FreeSparta.com and FreePascal!
// Original version by keeper89.blogspot.com, 2011
// FPC version by Maciej Izak (hnb), 2014
program TArrayProjectSingle;
{$MODE DELPHI}
{$APPTYPE CONSOLE}
uses
SysUtils, Math, Types, Generics.Collections, Generics.Defaults;
function CompareIntReverse(constref Left, Right: Integer): Integer;
begin
Result := TCompare.Integer(Right, Left);
end;
type
TForCompare = class
public
function CompareIntReverseMethod(constref Left, Right: Integer): Integer;
end;
function TForCompare.CompareIntReverseMethod(constref Left, Right: Integer): Integer;
begin
Result := TCompare.Integer(Right, Left);
end;
procedure PrintMatrix(A: TIntegerDynArray);
var
item: Integer;
begin
for item in A do
Write(item, ' ');
Writeln; Writeln;
end;
var
A: TIntegerDynArray;
FoundIndex: PtrInt;
ForCompareObj: TForCompare;
begin
WriteLn('Working with TArray - one-dimensional integer array');
WriteLn;
// Fill a one-dimensional array of integers by random numbers [1 .. 10]
A := TIntegerDynArray.Create(1, 6, 3, 2, 9);
// Print out what happened
Writeln('The original array:');
PrintMatrix(A);
// Sort ascending without comparator
TArrayHelper<Integer>.Sort(A);
Writeln('Ascending Sort without parameters:');
PrintMatrix(A);
// ! FPC don't support anonymous methods yet
// Sort descending, the comparator is constructed
// using an anonymous method
//TArray.Sort<Integer>(A, TComparer<Integer>.Construct(
// function (const Left, Right: Integer): Integer
// begin
// Result := Math.CompareValue(Right, Left)
// end));
// Sort descending, the comparator is constructed
// using an method
TArrayHelper<Integer>.Sort(A, TComparer<Integer>.Construct(
ForCompareObj.CompareIntReverseMethod));
Writeln('Descending by TComparer<Integer>.Construct(ForCompareObj.Method):');
PrintMatrix(A);
// Again sort ascending by using defaul
TArrayHelper<Integer>.Sort(A, TComparer<Integer>.Default);
Writeln('Ascending by TComparer<Integer>.Default:');
PrintMatrix(A);
// Again descending using own comparator function
TArrayHelper<Integer>.Sort(A, TComparer<Integer>.Construct(CompareIntReverse));
Writeln('Descending by TComparer<Integer>.Construct(CompareIntReverse):');
PrintMatrix(A);
// Searches for a nonexistent element
Writeln('BinarySearch nonexistent element');
if TArrayHelper<Integer>.BinarySearch(A, 5, FoundIndex) then
Writeln('5 is found, its index ', FoundIndex)
else
Writeln('5 not found!');
Writeln;
// Search for an existing item with default comparer
Writeln('BinarySearch for an existing item ');
if TArrayHelper<Integer>.BinarySearch(A, 6, FoundIndex) then
Writeln('6 is found, its index ', FoundIndex)
else
Writeln('6 not found!');
Writeln;
// Search for an existing item with custom comparer
Writeln('BinarySearch for an existing item with custom comparer');
if TArrayHelper<Integer>.BinarySearch(A, 6, FoundIndex,
TComparer<Integer>.Construct(CompareIntReverse)) then
Writeln('6 is found, its index ', FoundIndex)
else
Writeln('6 not found!');
Writeln;
Readln;
end.
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