1569.Number-of-Ways-to-Reorder-Array-to-Get-Same-BST.cpp | Long Code -> Concise Code

Hello Sir,hope you are doing great. The Code for 1569 LC seems to be overly exaggerated and long. Hence, I wanted to contribute a version2 for the 1569, which is short and easy to understand. 
[Ideone Link to the Code:](https://ideone.com/B2qh7O)