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[0..15000] 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:=0;
 for i:=1 to m do
  begin
  f[i]:=1;
  readln(time[i],x[i],y[i]);
  for j:=i-1 downto 1 do
   if time[i]-time[j]>=abs(x[i]-x[j])+abs(y[i]-y[j])
   then f[i]:=max(f[i],f[j]+1);
  ans:=max(ans,f[i]);
  end;
 writeln(ans);
 end;
begin
 main;
end.