var a:array[1..100005]of longint;
    n,i,bj:integer;
begin
 readln(n);
 while n<>0 do
 begin
  bj:=1;
  for i:=1 to n do read(a[i]);readln;
  for i:=1 to n do
   if a[a[i]]<>i then begin bj:=0;break;end;
  if bj=0 then writeln('not ambiguous')
          else writeln('ambiguous');
  readln(n);
 end;
end.

• Re:大家帮我看看，Why WA?(PASCAL) (16) wy54224 2011-02-12 15:59:13