The vertex of a binary tree is called an single child if it has a father's vertex but does not have a neighbor.
The root is not considered an single child.
let mark in numOnly a number of vertices in T that hold the attribute "single son ", and ‘with n we mark the total number of vertices in the T tree.
Is it true that every binary tree called "T" if numOnly/n<=0.5
then the height of "T" maintains the condition: height(T)=O(logn)?