文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

Unique Binary Search Trees

2. Solution

• 参考
  DP Solution in 6 lines with explanation. F(i, n) = G(i-1) * G(n-i)

class Solution {
public:
    int numTrees(int n) {
        int total[n + 1];
        total[0] = total[1] = 1;
        for(int i = 2; i <= n; i++) {
            total[i] = 0;
            for(int j = 1; j <= i; j++) {
                total[i] += total[j - 1] * total[i - j];
            }
        }
        return total[n];
    }
};

Reference

1. https://leetcode.com/problems/unique-binary-search-trees/description/