#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param num int整型一维数组 
# @return int整型二维数组
#
class Solution:
    def permute(self , num: List[int]) -> List[List[int]]:
        # write code here
        n=len(num)
        ans=[]
        path=[]
        def backtrack(path,i,nums):
            if i==n:
                ans.append(path.copy())
            for x in nums:
                path.append(x)
                backtrack(path,i+1,nums-{x})
                path.pop()
        backtrack(path,0,set(num))
        return ans