我有多个数组,它们都以整数字段开头,从1到5个字段不等,这些像索引一样的字段需要按照从小到大的顺序排序:
TArrayA = record
Field1:integer;
Field2:integer;
Field3:integer;
Field4:integer;
Field5:integer;
... //other fields, strings, integers... up to 50 fields
end;
ArrayA:=array of TArrrayA;
目前我使用以下方法进行排序:
// sort by Field1
top:=Length(ArrayA);
for counter := 0 to top do
begin
min := counter;
for look := counter + 1 to top do
if ArrayA[look].Field1 < ArrayA[min].Field1 then
min := look;
vTmpRecord := ArrayA[min];
ArrayA[min] := ArrayA[counter];
ArrayA[counter] := vTmpRecord;
end;
// now sort by Field2
top:=Length(ArrayA);
for counter := 0 to top do
begin
min := counter;
for look := counter + 1 to top do
if (ArrayA[look].Field1 = ArrayA[min].Field1) And
(ArrayA[look].Field2 < ArrayA[min].Field2) then
min := look;
vTmpRecord := ArrayA[min];
ArrayA[min] := ArrayA[counter];
ArrayA[counter] := vTmpRecord;
end;
这个代码能够完成工作。但是当我需要对所有5个字段进行排序时,它有些慢,所以我只能一个字段一个字段地进行排序,需要对数组进行5次排序。是否有更好、更快的方法?
以下是一个例子:
procedure TForm1.Button8Click(Sender: TObject);
type
TArrayA = record
Field1: integer;
Field2: integer;
Field3: integer;
Field4: integer;
Field5: integer;
end;
var
ArrayA: array of TArrayA;
vTmpRecord: TArrayA;
top, counter, min, max, look: integer;
i,t1,t2:integer;
begin
SetLength(ArrayA,100000);
for i := 0 to 99999 do
begin
ArrayA[i].Field1:=1+Random(100);
ArrayA[i].Field2:=1+Random(100);
ArrayA[i].Field3:=1+Random(100);
ArrayA[i].Field4:=1+Random(100);
ArrayA[i].Field5:=1+Random(100);
end;
t1:=GetTickCount;
// sort by Field1
top := Length(ArrayA);
for counter := 0 to top do
begin
min := counter;
for look := counter + 1 to top do
if ArrayA[look].Field1 < ArrayA[min].Field1 then
min := look;
vTmpRecord := ArrayA[min];
ArrayA[min] := ArrayA[counter];
ArrayA[counter] := vTmpRecord;
end;
// sort by Field2
top := Length(ArrayA);
for counter := 0 to top do
begin
min := counter;
for look := counter + 1 to top do
if (ArrayA[look].Field1 = ArrayA[min].Field1) and
(ArrayA[look].Field2 < ArrayA[min].Field2) then
min := look;
vTmpRecord := ArrayA[min];
ArrayA[min] := ArrayA[counter];
ArrayA[counter] := vTmpRecord;
end;
// sort by Field3
top := Length(ArrayA);
for counter := 0 to top do
begin
min := counter;
for look := counter + 1 to top do
if (ArrayA[look].Field1 = ArrayA[min].Field1) and (ArrayA[look].Field2 = ArrayA[min].Field2) and
(ArrayA[look].Field3 < ArrayA[min].Field3) then
min := look;
vTmpRecord := ArrayA[min];
ArrayA[min] := ArrayA[counter];
ArrayA[counter] := vTmpRecord;
end;
// sort by Field4
top := Length(ArrayA);
for counter := 0 to top do
begin
min := counter;
for look := counter + 1 to top do
if (ArrayA[look].Field1 = ArrayA[min].Field1) and (ArrayA[look].Field2 = ArrayA[min].Field2) and (ArrayA[look].Field3 = ArrayA[min].Field3) and
(ArrayA[look].Field4 < ArrayA[min].Field4) then
min := look;
vTmpRecord := ArrayA[min];
ArrayA[min] := ArrayA[counter];
ArrayA[counter] := vTmpRecord;
end;
// sort by Field5
top := Length(ArrayA);
for counter := 0 to top do
begin
min := counter;
for look := counter + 1 to top do
if (ArrayA[look].Field1 = ArrayA[min].Field1) and (ArrayA[look].Field2 = ArrayA[min].Field2) and (ArrayA[look].Field3 = ArrayA[min].Field3) and (ArrayA[look].Field4 = ArrayA[min].Field4) and
(ArrayA[look].Field5 < ArrayA[min].Field5) then
min := look;
vTmpRecord := ArrayA[min];
ArrayA[min] := ArrayA[counter];
ArrayA[counter] := vTmpRecord;
end;
t2:=GetTickCount;
Button8.Caption:=IntToStr(t2-t1);
end;