Add new DigitPowerSum routine to Maths category

Added new source code file.

Updated maths.ini with meta data for DigitPowerSum. Also updated SeeAlso
fields of related DigitSum and DigitSumBase routines.

Author: delphidabbler

collection/661.dat

@@ -0,0 +1,27 @@
+function DigitPowerSum(N: Integer; const Base: Byte; const Exponent: Byte):
+  Int64;
+var
+  SignOfN: Math.TValueSign;
+  Digit: Integer;
+  PowerDigit: Int64;
+begin
+  if Base < 2 then
+    raise SysUtils.EArgumentException.Create(
+      'Base must be in the range 2..255'
+    );
+  if N = 0 then
+    Exit(0);
+  SignOfN := Math.Sign(N);
+  N := Abs(N);
+  Result := 0;
+  repeat
+    Digit := N mod Base;
+    PowerDigit := PowNZN(Digit, Exponent);
+    if High(Int64) - PowerDigit < Abs(Result) then
+      raise SysUtils.EOverflow.Create('Overflow calculating digit power sum');
+    Result := Result + PowerDigit;
+    N := N div Base;
+  until N = 0;
+  if SignOfN = Math.NegativeValue then
+    Result := -1 * Result;
+end;

collection/maths.ini

@@ -620,7 +620,7 @@ Extra="<p>Sums of digits of negative numbers are negative, for example <mono>Dig
 TestInfo=advanced
 AdvancedTest.Level=unit-tests
 AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
-SeeAlso=DigitSumBase
+SeeAlso=DigitSumBase,DigitPowerSum
 Snip=418.dat
 Delphi2=N
 Delphi3=N
@@ -1763,7 +1763,7 @@ DisplayName="DigitSumBase"
 DescEx="<p>Calculates the sum of all the digits of integer <var>N</var> when epxressed in base <var>Base</var>. The returned value has the same sign as <var>N</var>.</p><p>Bases up to 255 are supported. If <var>Base</var> &lt; 2 then an <var>EArgumentException</var> exception is raised.</p>"
 Kind=routine
 Units=SysUtils,Math
-SeeAlso=DigitSum
+SeeAlso=DigitSum,DigitPowerSum
 TestInfo=advanced
 AdvancedTest.Level=unit-tests
 AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
@@ -1798,3 +1798,17 @@ AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tes
 Snip=659.dat
 DelphiXE=Y
 Delphi12A=Y
+
+[DigitPowerSum]
+DisplayName=DigitPowerSum
+DescEx="<p>Calculates the sum of all the digits of integer <var>N</var> in base <var>Base</var> where each digit is raised to the power <var>Exponent</var>. The returned value has the same sign as <var>N</var>.</p><p>If the result is too large to be represented as an <var>Int64</var> value then an <var>EOverflow</var> exception is raised.</p><p>Bases up to 255 are supported. If <var>Base</var> &lt;= 2 then an <var>EArgumentException</var> exception is raised.</p>"
+Kind=routine
+Units=SysUtils,Math
+Depends=PowNZN
+SeeAlso=DigitSum,DigitSumBase
+TestInfo=advanced
+AdvancedTest.Level=unit-tests
+AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
+Snip=661.dat
+DelphiXE=Y
+Delphi12A=Y