class Solution:    # @param num, a list of integer    # @return a list of lists of integers    def permute(self, num):        length=len(num)        if length==1:            return [num]        else:            res=[]            for i in range(length):                d=self.permute(num[0:i]+num[i+1:length])                for j in d:                    res.append(j+[num[i]])            #去除重复项            k=len(res)-1            while k>0:                for j in range(k):                    if self.IsSameList(res[j], res[k]):                        del res[k]                        break                k-=1               return res            def IsSameList(self,A,B):        an=len(A)        bn=len(B)        if (an!=bn):            return False        else:            for i in range(an):                if (A[i]!=B[i]):                    return False            return True         if __name__==‘__main__‘:    num=[1,2,3]    s=Solution()    print(s.permute([1,1,3]))