shuttle.pas

来自「Magio牛的usaco源代码」· PAS 代码 · 共 57 行

{
ID:maigoak1
PROG:shuttle
}

program shuttle;
var
  fin,fout:text;
  sign:-1..1;
  n,p,i,j,steps:byte;
procedure out;
  begin
    inc(steps);
    if steps mod 20=1 then begin
      if steps>1 then writeln(fout)
    end
    else
      write(fout,' ');
    write(fout,p);
  end;
begin
  assign(fin,'shuttle.in');
  reset(fin);
  readln(fin,n);
  close(fin);

  assign(fout,'shuttle.out');
  rewrite(fout);
  p:=n+1;sign:=-1;steps:=0;
  for i:=1 to n do begin
    for j:=1 to i-1 do begin
      p:=p+sign*2;
      out;
    end;
    p:=p+sign;
    out;
    sign:=-sign;
  end;

  for i:=1 to n do begin
    p:=p+sign*2;
    out;
  end;

  for i:=n downto 1 do begin
    sign:=-sign;
    p:=p+sign;
    out;
    for j:=1 to i-1 do begin
      p:=p+sign*2;
      out;
    end;
  end;
  writeln(fout);
  close(fout);
end.