[Day40]-[回溯]- 子集

输入：nums = [1,2,3]输出：[[],[1],[2],[1,2],[3],[1,3],[2,3],[1,2,3]]

输入：nums = [0]输出：[[],[0]]

func TestSubsets(t *testing.T) {	var res [][]int                                        // 接收的结果集	var subsets func(nums []int) [][]int                   // 子集	var backTrack func(nums []int, start int, track []int) // 回溯处理	backTrack = func(nums []int, start int, track []int) {		// var tmp = make([]int, len(track))		// copy(tmp, track)		// res = append(res, tmp)		// 将路径写入到结果集中，注意数组的深度复制 copy		res = append(res, append([]int{}, track...)) // 添加路径		for i := start; i < len(nums); i++ {			track = append(track, nums[i])  // 做选择			backTrack(nums, i+1, track)     // 递归回溯			track = track[0 : len(track)-1] // 撤销选择		}	}	subsets = func(nums []int) [][]int {		backTrack(nums, 0, []int{})		return res	}	t.Log(subsets([]int{1, 2, 3}))}