Driver Code
public static void Main ( string [ ] args ) { GFG tree = new GFG ( ) ; char [ ] arr = new char [ ] { ' D ' , ' B ' , ' E ' , ' A ' , ' F ' , ' C ' } ; char [ ] pre = new char [ ] { ' A ' , ' B ' , ' D ' , ' E ' , ' C ' , ' F ' } ; int len = arr . Length ; Node root = tree . buildTree ( arr , pre , 0 , len - 1 ) ;