Solution.go

func subsetsWithDup(nums []int) (ans [][]int) {
	slices.Sort(nums)
	n := len(nums)
	t := []int{}
	var dfs func(int)
	dfs = func(i int) {
		if i >= n {
			ans = append(ans, slices.Clone(t))
			return
		}
		t = append(t, nums[i])
		dfs(i + 1)
		t = t[:len(t)-1]
		for i+1 < n && nums[i+1] == nums[i] {
			i++
		}
		dfs(i + 1)
	}
	dfs(0)
	return
}