Unique Binary Search Trees

Unique Binary Search TreesAug 27 '123164
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Given n, how many structurally unique BST's (binary search trees) that store values 1...n?

For example,
Given n = 3, there are a total of 5 unique BST's.

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

class Solution {public:    int mh[10000];    int h(int n)    {        if(mh[n] != 0)            return mh[n];        mh[n] = (4*n-2)*h(n-1) / (n + 1);        return mh[n];    }    int numTrees(int n) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        mh[1] = 1;        mh[0] = 1;        return h(n);    }};