ac1096.pas

某牛人写的acm.tongji.edu.cn上大部分ac的代码,仅供学习研究,请不要用来作弊

program tju1096;
var
  s:ansistring;
function code(s:ansistring):ansistring;
  var
    l:word;
    a,b:ansistring;
  begin
    l:=length(s) shr 1;
    if l=0 then
      if s='0' then code:='A' else code:='B'
    else begin
      a:=code(copy(s,1,l));b:=code(copy(s,l+1,l));
      if (a[1]=b[1]) and (a[1] in ['A','B']) then code:=a else code:='C'+a+b;
    end;
  end;
begin
  repeat
    readln(s);
    writeln(code(s));
  until seekeof;
end.