nlogn的最长不下降子序列【tyvj1254挑选士兵】

var
  a,d:Array[-1..300000]of longint;
  i,n,m,k,l:longint;
function erfen(x:longint):longint;
  var mid,h,t:longint;
  begin
  h:=1;t:=l;
  erfen:=0;
  while h<=t do
    begin
    mid:=(h+t)shr 1;
    if d[mid]<=x then
      begin erfen:=mid;h:=mid+1;end
    else
      t:=mid-1;
    end;
  end;

begin
  readln(n);
  for i:=1 to n do
    read(a[i]);
  d[0]:=-maxlongint; l:=0;
  for i:=1 to n do
    if a[i]>=d[l] then
      begin
      inc(l);
      d[l]:=a[i];
      end
    else
      begin
      k:=erfen(a[i]);
      if a[i]<d[k+1] then d[k+1]:=a[i];
      end;
  writeln(l);
  end.