Data commit

Task/Parallel-calculations/Delphi/parallel-calculations.delphi

@@ -0,0 +1,94 @@
+program Parallel_calculations;
+
+{$APPTYPE CONSOLE}
+
+uses
+  System.SysUtils,
+  System.Threading,
+  Velthuis.BigIntegers;
+
+function IsPrime(n: BigInteger): Boolean;
+var
+  i: BigInteger;
+begin
+  if n <= 1 then
+    exit(False);
+
+  i := 2;
+  while i < BigInteger.Sqrt(n) do
+  begin
+    if n mod i = 0 then
+      exit(False);
+    inc(i);
+  end;
+
+  Result := True;
+end;
+
+function GetPrimes(n: BigInteger): TArray<BigInteger>;
+var
+  divisor, next, rest: BigInteger;
+begin
+  divisor := 2;
+  next := 3;
+  rest := n;
+  while (rest <> 1) do
+  begin
+    while (rest mod divisor = 0) do
+    begin
+      SetLength(Result, Length(Result) + 1);
+      Result[High(Result)] := divisor;
+      rest := rest div divisor;
+    end;
+    divisor := next;
+    next := next + 2;
+  end;
+end;
+
+function Min(l: TArray<BigInteger>): BigInteger;
+begin
+  if Length(l) = 0 then
+    exit(0);
+
+  Result := l[0];
+  for var v in l do
+    if v < result then
+      Result := v;
+end;
+
+const
+  n: array of Uint64 = [12757923, 12878611, 12757923, 15808973, 15780709, 197622519];
+
+var
+  m: BigInteger;
+  len, j, i: Uint64;
+  l: TArray<TArray<BigInteger>>;
+
+begin
+  j := 0;
+  m := 0;
+  len := length(n);
+  SetLength(l, len);
+
+  TParallel.for (0, len - 1,
+    procedure(i: Integer)
+    begin
+      l[i] := getPrimes(n[i]);
+    end);
+
+  for i := 0 to len - 1 do
+  begin
+    var _min := Min(l[i]);
+    if _min > m then
+    begin
+      m := _min;
+      j := i;
+    end;
+  end;
+
+  writeln('Number ', n[j].ToString, ' has largest minimal factor:');
+  for var v in l[j] do
+    write(' ', v.ToString);
+
+  readln;
+end.