491. 递增子序列

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
class Solution:
def findSubsequences(self, nums: List[int]) -> List[List[int]]:
path,result = [],[]
def split_tree(nums,start_index) -> List[List[int]]:
print(path)
if len(path)>=2:
result.append(path.copy())
# 这样 不是求 叶子结点 内容的 回溯,不写基线条件也没关系。因为for会自动停下,我们要记录的东西记录完就OK了;
used = set() # 每一层,不能有重复加进去的元素。
for i in range(start_index,len(nums)):
if (nums[i] in used) or (path!=[] and (nums[i]<path[-1])):
continue
used.add(nums[i])

path.append(nums[i])
split_tree(nums,i+1)
path.pop()
return result
return split_tree(nums,0)