{
  Solutions to the Advent Of Code.
  Copyright (C) 2024  Stefan Müller

  This program is free software: you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free Software
  Foundation, either version 3 of the License, or (at your option) any later
  version.

  This program is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License along with
  this program.  If not, see <http://www.gnu.org/licenses/>.
}

unit UPolynomialTestCases;

{$mode ObjFPC}{$H+}

interface

uses
  Classes, SysUtils, fpcunit, testregistry, UPolynomial, UBigInt;

type

  { TBigIntPolynomialTestCase }

  TBigIntPolynomialTestCase = class(TTestCase)
  private
    procedure TestCreateWithDegree(const ACoefficients: array of TBigInt; const ADegree: Integer);
  published
    procedure TestCreate;
    procedure TestCreateDegreeZero;
    procedure TestEqual;
    procedure TestUnequalSameLength;
    procedure TestUnequalDifferentLength;
    procedure TestTrimLeadingZeros;
    procedure TestCalcValueAt;
    procedure TestSignVariations;
    procedure TestScaleByPowerOfTwo;
    procedure TestScaleVariable;
    procedure TestScaleVariableByPowerOfTwo;
    procedure TestTranslateVariableByOne;
    procedure TestRevertOrderOfCoefficients;
    procedure TestDivideByVariable;
  end;

implementation

{ TBigIntPolynomialTestCase }

procedure TBigIntPolynomialTestCase.TestCreateWithDegree(const ACoefficients: array of TBigInt; const ADegree: Integer);
var
  a: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create(ACoefficients);
  AssertEquals('Degree of created polynomial incorrect.', ADegree, a.Degree);
end;

procedure TBigIntPolynomialTestCase.TestCreate;
begin
  TestCreateWithDegree([992123, 7, 20, 4550022], 3);
end;

procedure TBigIntPolynomialTestCase.TestCreateDegreeZero;
begin
  TestCreateWithDegree([4007], 0);
  TestCreateWithDegree([], 0);
  TestCreateWithDegree([0], 0);
end;

procedure TBigIntPolynomialTestCase.TestEqual;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([10, 7, 5, 1034]);
  b := TBigIntPolynomial.Create([10, 7, 5, 1034]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

procedure TBigIntPolynomialTestCase.TestUnequalSameLength;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([103, 7, 5, 10]);
  b := TBigIntPolynomial.Create([1034, 7, 5, 10]);
  AssertTrue('Polynomials are equal.', a <> b);
end;

procedure TBigIntPolynomialTestCase.TestUnequalDifferentLength;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([40000, 10, 7, 5, 1034]);
  b := TBigIntPolynomial.Create([10, 7, 5, 1034]);
  AssertTrue('Polynomials are equal.', a <> b);
end;

procedure TBigIntPolynomialTestCase.TestTrimLeadingZeros;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([10, 7, 5, 1034, 0, 0]);
  b := TBigIntPolynomial.Create([10, 7, 5, 1034]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

procedure TBigIntPolynomialTestCase.TestCalcValueAt;
var
  a: TBigIntPolynomial;
  exp: TBigInt;
begin
  a := TBigIntPolynomial.Create([80, 892477222, 0, 921556, 7303]);
  exp:= TBigInt.FromInt64(16867124285);
  AssertTrue('Polynomial evaluation unexpected.', a.CalcValueAt(15) = exp);
end;

procedure TBigIntPolynomialTestCase.TestSignVariations;
var
  a: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([-10, 15, 0, 10, -20, -15, 0, 0, 5, 10, -10]);
  AssertEquals(4, a.CalcSignVariations);
end;

procedure TBigIntPolynomialTestCase.TestScaleByPowerOfTwo;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([10, 7, 5, 1034]).ScaleByPowerOfTwo(7);
  b := TBigIntPolynomial.Create([128 * 10, 128 * 7, 128 * 5, 128 * 1034]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

procedure TBigIntPolynomialTestCase.TestScaleVariable;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([10, 7, 5, 1034]).ScaleVariable(TBigInt.FromInt64(10));
  b := TBigIntPolynomial.Create([10, 70, 500, 1034000]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

procedure TBigIntPolynomialTestCase.TestScaleVariableByPowerOfTwo;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([10, 7, 5, 1034]).ScaleVariableByPowerOfTwo(5);
  b := TBigIntPolynomial.Create([10, 7 * 32, 5 * 32 * 32, 1034 * 32 * 32 * 32]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

procedure TBigIntPolynomialTestCase.TestTranslateVariableByOne;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([10, 7, 5, 1034]).TranslateVariableByOne;
  b := TBigIntPolynomial.Create([1056, 3119, 3107, 1034]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

procedure TBigIntPolynomialTestCase.TestRevertOrderOfCoefficients;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([0, 10, 7, 5, 1034]).RevertOrderOfCoefficients;
  b := TBigIntPolynomial.Create([1034, 5, 7, 10]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

procedure TBigIntPolynomialTestCase.TestDivideByVariable;
var
  a, b: TBigIntPolynomial;
begin
  a := TBigIntPolynomial.Create([0, 10, 7, 5, 1034]).DivideByVariable;
  b := TBigIntPolynomial.Create([10, 7, 5, 1034]);
  AssertTrue('Polynomials are not equal.', a = b);
end;

initialization

  RegisterTest('Helper', TBigIntPolynomialTestCase);
end.