题目:
给定一个整数 n,求以 1 ... n 为节点组成的二叉搜索树有多少种?
解题思路:
继续:
class Solution: def numTrees(self, n): """ :type n: int :rtype: int """ G = [0]*(n+1) G[0], G[1] = 1, 1 for i in range(2, n+1): for j in range(1, i+1): G[i] += G[j-1] * G[i-j] return G[n]