#tree

Question

formule for

1.number of binary tree

2.number of binary search tree

3.number labeled binary tree

4.number of unlabeled binary tree

Answer 1

1 Number of Binary trees with n unlabeled nodes  is C(2n,n) / (n+1)

2.Number of Binary  trees with n labeled nodes  is  ( n! * C(2n,n) ) / (n+1). 

3.Number of Binary search trees with n keys is C(2n,n) / (n+1)