Structurally Unique BST

PROBLEM :

Given an interger N, how many structurally unique binary search trees are there that store values 1...N?

For example, for N = 2, there are 2 unique BSTs

     1              2
      \            /
       2          1
For N = 3, there are 5 possible BSTs

  1              3        3         2      1
    \           /          /         /  \      \
     3        2         1         1   3      2
    /       /             \                        \
   2      1               2                       3

Input:
First line contains the test cases T.  1<=T<=15
Each test case have one line which is an interger N.  1<=N<=11

Example:
Input:
2
2
3

Output:
2
5
     
--------------------------------------------------------------------------------
SIMPLE c++ IMPLEMENTATION :
--------------------------------------------------------------------------------

#include<iostream>
using namespace std;
int main()
 {
int t,no,i ;
long long num,den ;
cin>>t ;
while(t--)
{
   cin>>no ;
 
   //apply formula 2nCn/n+1
 
   num=1 ;
   for(i=no*2;i>no;i--)
       num=num*i ;
 
   den=1 ;
   for(i=1;i<=no;i++)
       den=den*i ;
     
   den=den*(no+1) ;
 
   cout<<num/den<<endl ;
}
return 0;
}

---------------------------------------------------------------------------------

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