'示例 1:
'輸入: nums = [1,1,2]
'輸出:  [[1,1,2], [1,2,1], [2,1,1]]
'示例 2:
'輸入: nums = [1,2,3]
'輸出: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
Public path As New Collection
Public used(2) As Boolean
Public k As Long
Public res_str

Sub 回溯演算法_全排列_元素重複_樹層去重()
    k = 0
    Sheet7.Cells.ClearContents
    nums 
 
= Array(1, 1, 2)
    nums = Arrays.sort(nums)
    Call permuteHelper(nums)
End Sub

Public Sub permuteHelper(nums)
    If path.count = UBound(nums) + 1 Then
        k = k + 1
        s = path(1) & path(2) & path(3)
        Sheet7.Cells(k, 1) = s
    End If
    For i = 0 To UBound(nums)
        If i 
 
> 0 Then
            If nums(i) = nums(i - 1) And used(i - 1) = False Then GoTo 10000
        End If
        If used(i) = False Then
            used(i) = True
            path.Add (nums(i))
            permuteHelper (nums)
            path.Remove (path.count)
            used(i) = False
        End If
 
10000
    Next
End Sub