🌵77. Combinations
https://leetcode.com/problems/combinations/
js
/**
* @param {number} n
* @param {number} k
* @return {number[][]}
*/
var combine = function(n, k) {
var result = []
helper(n, k, 1, [], result)
return result
}
function helper(n, k, m, nums, result) {
if (nums.length === k) {
result.push(nums.slice())
return
}
for (let i = m; i <= n; i++) {
nums.push(i)
helper(n, k, i + 1, nums, result)
nums.pop()
}
}py
class Solution(object):
def combine(self, n, k):
"""
:type n: int
:type k: int
:rtype: List[List[int]]
"""
result = []
self.helper(n, k, 1, [], result)
return result
def helper(self, n, k, m, nums, result):
if len(nums) == k:
result.append(nums[:])
return
for i in range(m, n + 1):
nums.append(i)
self.helper(n, k, i + 1, nums, result)
nums.pop()