Data commit

Task/N-smooth-numbers/Delphi/n-smooth-numbers.delphi

@@ -0,0 +1,196 @@
+program N_smooth_numbers;
+
+{$APPTYPE CONSOLE}
+{$R *.res}
+
+uses
+  System.SysUtils,
+  System.Generics.Collections,
+  Velthuis.BigIntegers;
+
+var
+  primes: TList<BigInteger>;
+  smallPrimes: TList<Integer>;
+
+function IsPrime(value: BigInteger): Boolean;
+var
+  v: BigInteger;
+begin
+  if value < 2 then
+    exit(False);
+
+  for v in [2, 3, 5, 7, 11, 13, 17, 19, 23] do
+  begin
+    if (value mod v) = 0 then
+      exit(value = v);
+  end;
+
+  v := 29;
+
+  while v * v < value do
+  begin
+    if (value mod v) = 0 then
+      exit(False);
+    inc(value, 2);
+    if (value mod v) = 0 then
+      exit(False);
+    inc(v, 4);
+  end;
+
+  Result := True;
+end;
+
+function Min(values: TList<BigInteger>): BigInteger;
+var
+  value: BigInteger;
+begin
+  if values.Count = 0 then
+    exit(0);
+
+  Result := values[0];
+  for value in values do
+  begin
+    if value < Result then
+      result := value;
+  end;
+end;
+
+function NSmooth(n, size: Integer): TList<BigInteger>;
+var
+  bn, p: BigInteger;
+  ok: Boolean;
+  i: Integer;
+  next: TList<BigInteger>;
+  indices: TList<Integer>;
+  m: Integer;
+begin
+  Result := TList<BigInteger>.Create;
+  if (n < 2) or (n > 521) then
+    raise Exception.Create('Argument out of range: "n"');
+
+  if (size < 1) then
+    raise Exception.Create('Argument out of range: "size"');
+
+  bn := n;
+  ok := false;
+  for p in primes do
+  begin
+    ok := bn = p;
+    if ok then
+      break;
+  end;
+
+  if not ok then
+    raise Exception.Create('"n" must be a prime number');
+
+  Result.Add(1);
+
+  for i := 1 to size - 1 do
+    Result.Add(0);
+
+  next := TList<BigInteger>.Create;
+
+  for p in primes do
+  begin
+    if p > bn then
+      Break;
+    next.Add(p);
+  end;
+
+  indices := TList<Integer>.Create;
+  for i := 0 to next.Count - 1 do
+    indices.Add(0);
+
+  for m := 1 to size - 1 do
+  begin
+    Result[m] := Min(next);
+    for i := 0 to indices.Count - 1 do
+      if Result[m] = next[i] then
+      begin
+        indices[i] := indices[i] + 1;
+        next[i] := primes[i] * Result[indices[i]];
+      end;
+  end;
+
+  indices.Free;
+  next.Free;
+end;
+
+procedure Init();
+var
+  i: BigInteger;
+begin
+  primes := TList<BigInteger>.Create;
+  smallPrimes := TList<Integer>.Create;
+  primes.Add(2);
+  smallPrimes.Add(2);
+
+  i := 3;
+  while i <= 521 do
+  begin
+    if IsPrime(i) then
+    begin
+
+      primes.Add(i);
+      if i <= 29 then
+        smallPrimes.Add(Integer(i));
+    end;
+    inc(i, 2);
+  end;
+
+end;
+
+procedure Println(values: TList<BigInteger>; CanFree: Boolean = False);
+var
+  value: BigInteger;
+begin
+  Write('[');
+  for value in values do
+    Write(value.ToString, ', ');
+  Writeln(']'#10);
+
+  if CanFree then
+    values.Free;
+end;
+
+procedure Finish();
+begin
+  primes.Free;
+  smallPrimes.Free;
+end;
+
+var
+  p: Integer;
+  ns: TList<BigInteger>;
+
+const
+  RANGE_3: array[0..2] of integer = (503, 509, 521);
+
+begin
+  Init;
+  for p in smallPrimes do
+  begin
+    Writeln('The first ', p, '-smooth numbers are:');
+    Println(NSmooth(p, 25), True);
+  end;
+
+  smallPrimes.Delete(0);
+  for p in smallPrimes do
+  begin
+    Writeln('The 3,000 to 3,202 ', p, '-smooth numbers are:');
+    ns := nSmooth(p, 3002);
+    ns.DeleteRange(0, 2999);
+    println(ns, True);
+  end;
+
+  for p in RANGE_3 do
+  begin
+    Writeln('The 3,000 to 3,019 ', p, '-smooth numbers are:');
+    ns := nSmooth(p, 30019);
+    ns.DeleteRange(0, 29999);
+    println(ns, True);
+  end;
+
+  Finish;
+  Readln;
+end.