InterviewBit Problems   Unique Binary Search Trees II : Unsolved

About the Unique Binary Search Trees II : Unsolved category (1)
Three line of easy c++ code (1)
C++ Solution Passes All Test Cases LOLLLLLLL (4)
Code on debugging returns 42 for test case 5, but on submission prints 70 (2)
Getting segmentation fault, please tell me why my solution is wrong (3)
No need to use anything just use formula 2n!/((n+1)!*n!)omment (1)
Another Catalan Number Problem (1)
Internal Error. We are working on fixing this issue ASAP (1)
Example not understood (2)
Constant time Solution (2)
O(n^2) solution is getting accepted here. But O(n) solution exist for the problem (3)