离散化Pascal模板

A：数的数组

k：数的个数

d[i]：离散化后i-1和i之间的距离

Procedure lsh(var a,d:array of real;k:longint);
Type
 rec=record
   pos:longint;
   num:real;
 end;
 
Var
 b:array[0..100000] of rec;
 i,now,last:longint;

Procedure qsort(var b:array of rec;l,r:longint);
var
 i,j:longint;
 x,y:rec;
  begin
  i:=l;j:=r;x:=b[random(r-l+1)+l];
    repeat
    while b[i].num<x.num do inc(i);
    while b[j].num>x.num do dec(j);
    if i<=j then
      begin
      y:=b[i];
      b[i]:=b[j];
      b[j]:=y;
      inc(i);
      dec(j);
    end;
  until i>j;
  if l<j then qsort(b,l,j);
  if i<r then qsort(b,i,r);
end;

  begin
  for i:=1 to k do
    with b[i] do
      begin
      num:=a[i];
      pos:=i;
    end;
  qsort(b,1,k);
  now:=1;
  d[1]:=b[1].num;
  a[b[1].pos]:=1;
  last:=1;
  for i:=2 to k do
    begin
    if b[i-1].num<>b[i].num then
      begin
      d[now+1]:=b[i].num-b[last].num;
      last:=i;
      inc(now);
    end;
    a[b[i].pos]:=now;
  end;
end;