输入13 超时
源程序:

program checker(input,output);
var
  a:array[0..15]of boolean;
  b:array[-15..15]of boolean;
  c:array[0..30]of boolean;
  num:array[0..15]of integer;
  n:integer;
  sum:longint;
  time:longint;
procedure try(ceng:integer);
  var i:integer;
  begin
    if ceng>n then
      begin
        inc(sum);
        if sum<=3 then
          begin
            for i:=1 to n-1 do write(num[i],' ');
            writeln(num[n]);
          end;
      end
    else for i:=1 to n do
      if (not a[i])and(not b[ceng-i])and(not c[ceng+i]) then
        begin
          a[i]:=true;
          b[ceng-i]:=true;
          c[ceng+i]:=true;
          num[ceng]:=i;
          try(ceng+1);
          a[i]:=false;
          b[ceng-i]:=false;
          c[ceng+i]:=false;
          num[ceng]:=0;
        end;
  end;
begin
  assign(input,'checker.in');
  assign(output,'checker.out');
  reset(input);
  rewrite(output);
{ time:=meml[$40:$6c];}
  readln(n);
  try(1);
  writeln(sum);
{ writeln((meml[$40:$6c]-time)/18.4:0:2);}
  close(input);
  close(output);
end.
帮我改一下