欢迎来到银盒子的世界~
啊啊啊，到了回溯
class Solution:
def __init__(self):
self.res=[]
self.path=[]
def backtracking(self,n,k,startindex):
if len(self.path)==k:
self.res.append(self.path[:])
return
for i in range(startindex,n+1):
self.path.append(i)
self.backtracking(n,k,i+1)
self.path.pop()
def combine(self, n: int, k: int) -> List[List[int]]:
self.backtracking(n,k,1)
return self.res