问题描述:

How many binary trees can find that have n Node and the height of these tress are n-3?

The total number of Binary Tree possible with `n`

nodes = **( ^{2n}C_{n}) / (n+1)**.

The minimum depth of a binary tree is **⌊log _{2}n⌋** and the maximum depth is

`n-1`

.So in each level level there will be **[( ^{2n}C_{n}) / (n+1)] / [(n-1) - (⌊log_{2}n⌋)]** nodes.