poj2014 不带修改区间第k大树

 1 type node1=record
 2      l,r,sum:longint;
 3      end;
 4      node2=record
 5      x,idx:longint;
 6      end;
 7 var q,i,j,k,tot,n,m:longint;
 8     a:array[0..500000] of node2;
 9     rank,root:array[0..500000] of longint;
10     t:array[0..5000000] of node1;
11 procedure qsort(h,l:longint);
12  var i,j,m:longint;
13      temp:node2;
14  begin
15  i:=h;j:=l;m:=a[(i+j)>>1].x;
16  repeat
17   while a[i].x<m do inc(i);
18   while a[j].x>m do dec(j);
19   if i<=j then
20    begin
21    temp:=a[i];a[i]:=a[j];a[j]:=temp;
22    inc(i);dec(j);
23    end;
24  until i>j;
25  if i<l then qsort(i,l);
26  if j>h then qsort(h,j);
27  end;
28 procedure insert(var x:longint;num,l,r:longint);
29  var mid:longint;
30  begin
31  t[tot]:=t[x];
32  x:=tot;
33  inc(tot);
34  inc(t[x].sum);
35  if l=r then exit;
36  mid:=(l+r)>>1;
37  if num<=mid then insert(t[x].l,num,l,mid)
38  else insert(t[x].r,num,mid+1,r);
39  end;
40 function query(i,j,k,l,r:longint):longint;
41  var mid,tmp:longint;
42  begin
43  if l=r then exit(l);
44  tmp:=t[t[j].l].sum-t[t[i].l].sum;
45  mid:=(l+r)>>1;
46  if k<=tmp then exit(query(t[i].l,t[j].l,k,l,mid))
47  else exit(query(t[i].r,t[j].r,k-tmp,mid+1,r));
48  end;
49 procedure main;
50  begin
51  t[0].l:=0;t[0].r:=0;t[0].sum:=0;root[0]:=0;
52  readln(n,m);
53  for i:=1 to n do begin read(a[i].x);a[i].idx:=i;end;
54  qsort(1,n);
55  tot:=1;
56  for i:=1 to n do rank[a[i].idx]:=i;
57  for i:=1 to n do
58   begin
59   root[i]:=root[i-1];
60   insert(root[i],rank[i],1,n);
61   end;
62  for q:=1 to m do
63   begin
64   readln(i,j,k);
65   writeln(a[query(root[i-1],root[j],k,1,n)].x);
66   end;
67  end;
68 begin
69  main;
70 end.