American_Heritage_(heritage)[USACO_3.4.2]

算法：递归

分析：树的基本操作，已知前序遍历和中序遍历求后序遍历。

      先确定根，再在中序遍历中确定左子树和右子树。

{

ID:1011mashuo

PROG:heritage

LANG:PASCAL

}



program heritage;



var

 zx,qx:ansistring;

 

procedure work(zx,qx:ansistring);

var

 t,len:longint;

begin

 if qx<>'' then

  begin

   len:=length(qx);

   t:=pos(qx[1],zx);

   work(copy(zx,1,t-1),copy(qx,2,t-1));

   work(copy(zx,t+1,len-t),copy(qx,t+1,len-t));

   write(qx[1]);

  end;

end;



begin

 assign(input,'heritage.in'); reset(input);

 assign(output,'heritage.out'); rewrite(output);



 readln(zx);

 readln(qx);

 work(zx,qx);

 writeln;



 close(input); close(output);

end.