Hi All,
I am trying to use some legacy Delphi QuickSort code.
The problem is that the original defines this var: Var d : ptrArray
Absolute da;and I have changed this in my version and it crashes with an error.
Project Island_maker.exe raised exception class 'External SIGSEGV'
I am trying to use my version of the code, not the original.
Original code ---Unit Qsort;
{
Copyright 1990 Trevor J CarlsenAll rights reserved.
Author: Trevor J Carlsen PO Box 568 Port Hedland WA 6721
A general purpose sorting Unit.
}
Interface
Type updown = (ascending,descending); str255 = String; dataType =
str255; { the Type of data to be sorted } dataptr = ^dataType; ptrArray
= Array[1..10000] of dataptr; Arrayptr = ^ptrArray; Const maxsize : Word =
10000; SortType : updown = ascending; Procedure QuickSort(Var da; left, right
: Word);
{============================================================================}Implementation
Procedure swap(Var a,b : dataptr); { Swap the Pointers } Var t : dataptr;
begin t := a; a := b; b := t; end; Procedure QuickSort(Var da;
left,right : Word); Var d : ptrArray Absolute da; pivot :
dataType; lower, upper, middle : Word;
begin lower := left; upper := right; middle:= (left + right) div 2;
pivot := d[middle]^; Repeat Case SortType of ascending : begin
While d[lower]^ < pivot do inc(lower);
While pivot < d[upper]^ do dec(upper); end; descending:
begin While d[lower]^ > pivot do inc(lower);
While pivot > d[upper]^ do dec(upper); end; end; {
Case } if lower <= upper then begin { swap the
Pointers not the data } swap(d[lower],d[upper]); inc(lower);
dec(upper); end; Until lower > upper; if left < upper then
QuickSort(d,left,upper); if lower < right then QuickSort(d,lower,right);
end; { QuickSort }
end.
My version-----Type map_detail = record Terrain :
Terrain_type; Terrain_char : char; description
: string; x, y, location_number : integer;
exits : exit_type; end;
island_single_type = array[ 1..(array_max_x * array_max_y) ] of
map_detail;
Type updown = (ascending, descending);
Const SortType : updown = ascending;
var Form1: TForm1; max_x, max_y, max_locations, start_x, start_y,
finish_x, finish_y : integer; island : island_2D_type; island_single_array :
island_single_type;
implementation
uses set_max;
{--------------------------------------------------------------------}
Procedure swap(Var a,b : map_detail); { Swap the Pointers } Var t :
map_detail; begin t := a; a := b; b := t;
end;{--------------------------------------------------------------------}
Procedure QuickSort( Var island_single_array : island_single_type; left, right
: integer); Var d : island_single_type; pivot : integer;
lower, upper, middle : integer;
begin lower := left; upper := right; middle:= (left + right) div 2;
pivot := island_single_array[middle].location_number; Repeat Case
SortType of ascending : begin While
island_single_array[lower].location_number < pivot do
inc(lower); While pivot <
island_single_array[upper].location_number do dec(upper);
end; descending: begin While
island_single_array[lower].location_number > pivot do
inc(lower); While pivot >
island_single_array[upper].location_number do dec(upper);
end; end; { Case } if lower <= upper then
begin { swap the Pointers not the data } swap(d[lower],d[upper]);
inc(lower); dec(upper); end; Until lower > upper; if
left < upper then QuickSort(d,left,upper); if lower < right then
QuickSort(d,lower,right); end; { QuickSort
}{--------------------------------------------------------------------}-----
--
_______________________________________________
Lazarus mailing list
Lazarus@lists.lazarus.freepascal.org
http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
