Leetcode 77:组合
class Solution:
def combine(self, n: int, k: int) -> List[List[int]]:
self.res = []
nums = list(range(1, n+1))
self.helper(nums, k , 0, [])
return self.res
def helper(self, nums, k, start, temp):
if len(temp) == k:
self.res.append(temp.copy())
return
for i in range(start, len(nums)):
temp.append(nums[i])
self.helper(nums,k, i+1, temp)
temp.pop()