下一个排列

class Solution(object):


    def cartesian_product(self,a,b):
        l = [] #空的集合
        for x in a: #x为a中所有的成员
            for y in b: #y为b中所有的成员
                kk=str(x)+str(y)
    #           print(kk)
                if len(set(kk))==len(kk):
                    l.append(kk) #将所有可能的“有序对”加到“空集合”中
        return l
    def nextPermutation(self, nums):
        """
        :type nums: List[int]
        :rtype: None Do not return anything, modify nums in-place instead.
        """

        c=self.cartesian_product(nums,nums)
        c=self.cartesian_product(nums,c)
        c.sort()
        #print(c)
        g = c.index(''.join([str(p) for p in nums]))
        #print(k)
        if g ==len(c)-1:
            print(-------------------'')
            return [int(k) for k in c[0]]
        else:
            #print(c[k+1])
            print([int(i) for i in c[g+1]])
            print('#####################################')
            kk=[int(m) for m in c[g+1]]
            return kk
a=[1,2,3]
c=Solution()
import time
t1=time.time()

#计算几个数之和，下面就填几
c1=c.nextPermutation( a)
print(time.time()-t1)

print(c1)