HNOI2004打鼹鼠（LIS)

大水题……

不过通过这题我们应该养成一个好习惯：好好看清题……

竟然没有看到时限 10sec……

 var i,j,n,m,ans:longint;
     f,time,x,y:array[..] of longint;
 function max(x,y:longint):longint;
  begin
  if x>y then exit(x) else exit(y);
  end;
 procedure main;
  begin
  readln(n,m);ans:=;
  for i:= to m do
   begin
   f[i]:=;
   readln(time[i],x[i],y[i]);
   for j:=i- downto  do
    if time[i]-time[j]>=abs(x[i]-x[j])+abs(y[i]-y[j])
    then f[i]:=max(f[i],f[j]+);
   ans:=max(ans,f[i]);
   end;
  writeln(ans);
  end;
 begin
  main;
 end.