Delphi - which object (multidimensional array, etc.) will work?

Question

I need to store the first ten values ​​in sorted order. My data structure:

TMyRecord = record
  Number: Integer;
  Value: Float;
end

I will calculate a bunch of float values. I need to save the top 10 values ​​of the float. Each value has an associated number. I want to add “sets” ... If my float value is above one of the top 10, it should add itself to the list, and then the “old” number 10, now 11, will be discarded. I should be able to access the list in an ordered order (float value) ...

It is almost like a TStringList that supports sorted order ....

Is there something like this already built into Delphi 2010?

Answer 1

Generics.Collections.TList<TMyRecord> .

TMyRecord = record
  Number: Integer;
  Value: Float;
end;

var
  Top10: TList<TMyRecord>;

Generics.Collections, .

:

Top10 := TList<TMyRecord>.Create;

:

procedure Add(const Item: TMyRecord);
var
  i: Integer;
begin
  for i := 0 to Top10.Count-1 do 
    if Item.Value>Top10[i].Value then
    begin
      Top10.Insert(i, Item);
      Top10.Count := Min(10, Top10.Count);
      exit;
    end;
  if Top10.Count<10 then
    Top10.Add(Item);
end;

. , .

Answer 2

, , , , , , , , , .

, , for, , 10:

if (Item.Value <= Top10[Top10.Count - 1].Value) and (Top10.Count = 10) then
  Exit;

, 10- , :

if (Item.Value <= Top10[9].Value) then
  Exit;

:

procedure Add(const Item: TMyRecord);
var
  i: Integer;
begin

  // Throw it out if it not bigger than our smallest top10
  if (Item.Value <= Top10[9].Value) then
    Exit;

  // Start at the bottom, since it more likely
  for i := 9 downto 1 do 
    if Item.Value <= Top10[i - 1].Value then
    begin
      // We found our spot
      Top10.Insert(i, Item);
      // We're always setting it to 10 now
      Top10.Count := 10;
      // We're done
      Exit;
    end;

  // Welcome, leader!
  Top10.Insert(0, Item);
  // We're always setting it to 10 now
  Top10.Count := 10;
end;

Answer 3

, TMyRecord, :

type
  TMyRecord = record 
    Number: Integer; 
    Value: Float; 
  end;

const
  MaxRecordsInTopTen = 10;

var
  TopTen: array[0..MaxRecordsInTopTen-1] of TMyRecord; 
  NumRecordsInTopTen: Integer = 0;

procedure CheckValueForTopTen(Value: Float; Number: Integer);
var
  I, J, NumToMove: Integer;
begin
  // see if the new Value is higher than an value already in the list
  for I := 0 to (NumRecordsInTopTen-1) do
  begin
    if Value > TopTen[I].Value then
    begin
      // new Value is higher then this value, insert before
      // it, moving the following values down a slot, and
      // discarding the last value if the list is full

      if NumRecordsInTopTen < MaxRecordsInTopTen then
        NumToMove := NumRecordsInTopTen - I
      else
        NumToMove := MaxRecordsInTopTen - I - 1;

      for J := 1 to NumToMove do
        Move(TopTen[NumRecordsInTopTen-J], TopTen[NumRecordsInTopTen-J-1], SizeOf(TMyRecord));

      // insert the new value now
      TopTen[I].Number := Number;
      TopTen[I].Value := Value;
      NumRecordsInTopTen := Min(NumRecordsInTopTen+1, MaxRecordsInTopTen);

      // all done
      Exit;
    end;
  end;

  // new value is lower then existing values,
  // insert at the end of the list if room
  if NumRecordsInTopTen < MaxRecordsInTopTen then
  begin
    TopTen[NumRecordsInTopTen].Number := Number;
    TopTen[NumRecordsInTopTen].Value := Value;
    Inc(NumRecordsInTopTen);
  end;
end;

Answer 4

, Object Pascal.

{$APPTYPE CONSOLE}
program test2; uses sysutils, windows;
  const
    MAX_VALUE = $7FFF;
    RANDNUMCOUNT = 1000;
  var
    topten: array[1..10] of Longint;
    i, j: integer;
    Value: Longint;
  begin
    randomize;
    FillChar(topten, Sizeof(topten), 0);
    for i := 1 to RANDNUMCOUNT do
      begin
        Value := Random(MAX_VALUE);
        j := 1;
        while j <= 10 do
          begin
            if Value > topten[j] then
              begin
                 Move(topten[j], topten[j+1], SizeOf(Longint) * (10-j));
                 topten[j] := Value;
                 break;
              end;
            inc(j);
          end;
     end;
    writeln('Top ten numbers generated were: ');
    for j := 1 to 10 do
      writeln(j:2, ': ', topten[j]);
    readln;
  end.