77. Combinations

class Solution:
    def combine(self, n: int, k: int):
        def dfs(num , k):
            if k == 0:
                answer.append(cur[:])
                return

            for i in range(num, n + 1):
                cur.append(i)
                dfs(i + 1, k - 1)
                cur.pop()

        answer = []
        cur = []

        dfs(1, k)

        return answer

itertools 사용
이게 훨씬 빠르니까 그냥 구하기만 하는거면 이거 써야함

import itertools

class Solution:
    def combine(self, n, k):
        return list(itertools.combinations(range(1, n + 1), k))

https://leetcode.com/problems/combinations/submissions/