题目描述

题解思路

遍历nums，让当前数字添加到结果前缀中，递归调用，直到前缀的长度为k，然后将前缀添加到结果集

题解代码

func combine(n int, k int) [][]int {var nums = make([]int, n)for i := n; i > 0; i-- {nums[i-1] = i}var res = make([][]int, 0)var dfs func(prefix []int, nums []int, k int)dfs = func(prefix []int, nums []int, k int) {if k == 0 {tmp := make([]int, len(prefix))copy(tmp[:], prefix[:])res = append(res, tmp)return}for i := 0; i <= len(nums) - k; i++ {dfs(append(prefix, nums[i]), nums[i+1:], k-1)}}dfs(make([]int, 0, k), nums, k)return res
}