driver program to test above functions
let In = [ 9 , 8 , 4 , 2 , 10 , 5 , 10 , 1 , 6 , 3 , 13 , 12 , 7 ] ; let pre = [ 1 , 2 , 4 , 8 , 9 , 5 , 10 , 10 , 3 , 6 , 7 , 12 , 13 ] ; let len = In . length ; let root = buildTree ( pre , In ) ; printInorder ( root ) ;