begin height(root)
If node is NULL
then return 0
Else
If left child and right child nodes are NULL
return 1
Else
take two integers let 'l' and 'r' to store value of left child and right child recursively
by using formula:
height_of_a_tree = 1 + (which-one is bigger from 'l' & 'r')
end height
begin internal_nodes( root )
If node is NULL
then return 0
If left child and right child nodes are NULL
return 0
Else
return 1 + internal_nodes( left child of node ) + internal_nodes( right child of node )
end internal_nodes
Number of internal nodes: 6.
100
\\
120
\\
130
\\
140
\\
150
\\
160
\\
170
Number of internal nodes: 3
100
/ \\
30 150
/ \\ / \\
20 50 122 188