def find_partitions(nums, m, index, subset1, subset2, result): # 如果子集1或子集2的和大于或等于数组总和，则停止当前路径的搜索 if sum(subset1) >= sum(nums) or sum(subset2) >= sum(nums): return # 检查当前子集和的差值是否等于M，如果是，则添加到结果中 if abs(sum(subset1) - sum(subset2)) == m: result.append((subset1[:], subset2[:])) # 继续搜索，将当前数字添加到子集1 if index < len(nums): subset1.append(nums[index]) find_partitions(nums, m, index + 1, subset1, subset2, result) subset1.pop() # 回溯，移除当前数字 # 继续搜索，将当前数字添加到子集2 subset2.append(nums[index]) find_partitions(nums, m, index + 1, subset1, subset2, result) subset2.pop() # 回溯，移除当前数字 def count_valid_combinations(n, m): nums = list(range(1, n + 1)) # 创建从1到n的数组 result = [] find_partitions(nums, m, 0, [], [], result) return len(result) # 返回满足条件的组合数量 # 读取输入的两个正整数N和M n, m = map(int, input().split()) # 计算并输出符合条件的拆分方案数 print(count_valid_combinations(n, m))