记录编号	3005	评测结果	AAWAWAAT
题目名称	[NOIP 2002]字串变换	最终得分	62
用户昵称	bly1991	是否通过	未通过
代码语言	Pascal	运行时间	1.014 s
提交时间	2008-09-30 09:37:21	内存使用	24.53 MiB

program bly(input,ouput);
var
  a:array[1..10,1..10000] of string;
  rule:array[1..6,1..2] of string;
  n,long,long0,deep,i,j,k,x:integer;
  p:boolean;
  st,st0:string;
  f1,f2:text;

  procedure th;
  var
    i0:integer;
  begin
    i0:=pos(rule[j,1],a[deep,i]);
    a[deep+1,long0]:=a[deep,i];
    delete(a[deep+1,long0],i0,length(rule[j,1]));
    insert(rule[j,2],a[deep+1,long0],i0);
    inc(long0);
  end;

begin
  assign(f1,'string.in');
  reset(f1);
  readln(f1,st);
  a[1,1]:=copy(st,1,pos(' ',st)-1);
  st0:=copy(st,pos(' ',st)+1,length(st)-1);
  repeat
    inc(n);
    readln(f1,st);
    rule[n,1]:=copy(st,1,pos(' ',st)-1);
    rule[n,2]:=copy(st,pos(' ',st)+1,length(st)-1);
  until eof(f1)=true;

  p:=false;
  deep:=1;
  long0:=1;
  repeat
    long:=long0;
    long0:=1;
    for i:=1 to long do begin
      for j:=1 to n do begin
        if pos(rule[j,1],a[deep,i])<>0 then th;
      end;
    end;
    for i:=1 to long0 do begin
      if a[deep+1,i]=st0 then p:=true;
    end;
    x:=long0;
    for i:=1 to long0 do begin
      for j:=i+1 to long0 do begin
        if (a[deep+1,i]=a[deep+1,j])and(a[deep+1,j]<>'') then begin
          for k:=j to long0-1 do a[deep+1,k]:=a[deep+1,k+1];
          dec(x);
        end;
      end;
    end;
    long0:=x;
    if not(p=true) then inc(deep);
  until (p=true)or(deep>=10);

  assign(f2,'string.out');
  rewrite(f2);
  if p=true then write(f2,deep);
  if deep>=10 then write(f2,'NO ANSWER');
  close(f2);
end.