OIer 1：
procedure qsort(l,r:longint);
var
i,j,m,t:longint;
begin
i:=l;
j:=r;
m:=a[(l+r) div 2];
repeat
while a[i]m do dec(j);
if ij;
if l <j then qsort(l,j);
if i <r then qsort(i,r);
end;OIer 2：
Procedure QuickSort(Left, Right : Longint);
Var
LeftPointer, RightPointer, Medium, Temp : Longint;
Begin
LeftPointer := Left;
RightPointer := Right;
Medium := a[(Left + Right) Shr 1];
Repeat
While a[LeftPointer] Medium Do
Dec(RightPointer);
If LeftPointer j;
If Left < RightPointer Then
QuickSort(Left,RightPointer);
If LeftPointer < Right Then
QuickSort(LeftPointer,Right);
End; {End Procedure}OIer 3：
procedure kuaipai(z,y:longint);var i,j,m,t:longint;begin i:=z;j:=y;m:=a[(z+y) div 2];repeat while a[i]m do dec(j);if ij;if z <j then kuaipai(z,j);if i <y then kuaipai(i,y);end;OIer 3 Pro：
program kuaipaiwithoutrecursive;{今天心情不好不想用递归}
var
sl,sr:array[1..1000] of longint;
i,j,n,t,p,r,x,q,t:longint;
begin
sl[1]:=1;
sr[1]:=n;
t:=1;
while t>0 do begin
p:=sl[t];
r:=sr[t];
t:=t-1;
if p <r then begin
x:=a[r];
i:=p-1;
for j:=p to r-1 do begin
if a[j] <=x then begin
i:=i+1;
t:=a[i];
a[i]:=a[j];
a[j]:=t;
end;
end;
t:=a[i+1];
a[i+1]:=a[r];
a[r]:=t;
q:=i+1;
t:=t+1;
sl[t]:=p;
sr[t]:=q-1;
t:=t+1;
sl[t]:=q+1;
sr[t]:=r;
end;
end;
end;