n, m = map(int, input().split(' '))MOD = 10**9 + 7from functools import lru_cachedef binary_tree(n, m):@lru_cache(maxsize=None) # 去除缓存限制# k是节点数,h是高度def dfs(k, h):if k == 0:return 1if h == 0:return 0if k == 1:return 1total = 0for i in range(k):# h-1高度下 左子树和右子树的 方案数left = dfs(i, h-1)right = dfs(k-i-1, h-1)total = (total + left * right) % MODreturn totalreturn dfs(n, m) % MODprint(binary_tree(n, m)) #牛客试题# 小强现在有个节点,他想请你帮他计算出有多少种不同的二叉树满足节点个数为且树的高度不超过的方案.因为答案很大,所以答案需要模上1e9+7后输出. 树的高度: 定义为所有叶子到根路径上节点个数的最大值.... https://www.nowcoder.com/questionTerminal/aaefe5896cce4204b276e213e725f3ea?answerType=1&f=discussion