记录编号	3373	评测结果	AAAATAAT
题目名称	[NOIP 2002]字串变换	最终得分	75
用户昵称	辨机ZN	是否通过	未通过
代码语言	Pascal	运行时间	2.009 s
提交时间	2008-10-06 19:59:06	内存使用	95.33 MiB

program ex(f1,f2);
 type
  zn=array [1..7,1..2] of string;
  hu=array [1..20000] of string;
  iu=array [1..350000] of string;
 var
  a:zn;  i,j,k,l,m,n,p,head,tail,step,tou,wei,l4:integer;
  f1,f2:text; flag,flag2:boolean;
  start,answer,s:string; c,c2:hu; tree:iu;
 procedure shuchu(u:integer);
  begin
   writeln(f2,u);
   close(f1);
   close(f2);
   halt;
  end;
 procedure insert(xx:string);
  var
   p,i,j,k:integer; flag:boolean;
  begin
   p:=1; flag:=true;
   while flag do
    begin
     if xx<tree[p] then
                    begin
                     p:=p*2;
                     if tree[p]='' then begin
                                        tree[p]:=xx;
                                        c[wei]:=xx;
                                        exit;
                                       end;
                    end

                   else
     if xx>tree[p] then
                    begin
                     p:=p*2+1;
                     if tree[p]='' then begin
                                        tree[p]:=xx;

                                        c[wei]:=xx;
                                        exit;
                                       end;
                    end

                   else
     if xx=tree[p] then begin dec(wei); exit; end;
   end;
  end;

 procedure chuli;
  var
   st,s2,se,s3,s4:string;
   i,j,m,k,q,k2:integer;
   flag:boolean;
  begin
   inc(step);
   for q:=head to tail do
    begin
     s2:=c[q];
     for i:=1 to n do
     begin
     st:=a[i,1]; se:=a[i,2];
     m:=pos(st,s2);
     if m>0 then
      begin
       inc(wei);
       s4:=copy(s2,1,m-1)+se+copy(s2,m+length(st),length(s2));
       insert(s4);
       if c[wei]=answer then shuchu(step);
      end;
     {pan duan chong fu}
     j:=0;  flag:=true; k2:=m; k:=m; s3:=s2; l4:=length(st);
     while flag do
      begin
       j:=j+l4;
       delete(s3,k2,j);
       k2:=pos(st,s3); k:=k2;
       if k>0 then
        begin
         k:=k+j;
         inc(wei);
         s4:=copy(s2,1,k-1)+se+copy(s2,k+length(st),length(s2));
         insert(s4);
         if c[wei]=answer then shuchu(step);
        end
              else
        flag:=false;
      end;
     end;
    end;
  end;
  begin
  assign(f1,'string.in'); reset(f1);
  assign(f2,'string.out'); rewrite(f2);
  readln(f1,s);
  start:=copy(s,1,pos(' ',s)-1);
  answer:=copy(s,pos(' ',s)+1,length(s));
  n:=0;

  while not(eof(f1)) do
   begin
    readln(f1,s);
    inc(n);
    a[n,1]:=copy(s,1,pos(' ',s)-1);
    a[n,2]:=copy(s,pos(' ',s)+1,length(s));
   end;
  head:=1; tail:=1;
  tou:=1; wei:=1;
  c[1]:=start;
  tree[1]:=c[1];
  for i:=1 to 10 do
   begin
    tou:=head; tail:=wei;
    chuli;
    head:=tail+1;
   end;

  writeln(f2,'NO ANSWER!');
  close(f1);
  close(f2);
 end.