InterviewBit Problems   Unique Binary Search Trees II : Solved

About the Unique Binary Search Trees II : Solved category (1)
[C++][Unique Binary Search Trees II] simple iterative (1)
Python 3.5 One-Liner (1)
Think recursive...optimise it...u r done (1)
5 lines soln with help (1)
Pure Recursive solution Accepted [JAVA] (1)
Dp CPP recursive Solution (1)
Lang: C++; Complexity[Time, Space]: [O(n*n), O(n)] (1)
O(1) space and O(n) easiest C++ solution (1)
O(n) solutionUsing binomial coefficient --- from tech dose yt (1)
Using Combinatorics (1)
C++ solution using concept of catlan number (1)
Simple 10Lines Code C++ (1)
Top-down approach (memoization) solution (1)
Simple implementation of Nth Catalan number (1)
Combinatorics solution (1)
Easiest c++ solution with comments (1)
Return N'th Catalan Number (1)
C++ solution to the problem (1)
The worst possible solution for this question (1)
This is exactly the same as Intersecting Chords (1)
What is the problem with this code Please help (3)