leetcode 外观数列

class Solution(object):
    def countAndSay(self, n):
        a='1'


        def count(pre):
            start=0
            end=0
            
            cur=''
            while end<len(pre):
                while end<len(pre) and pre[start]==pre[end]:
                    end+=1
                cur=cur+str(end-start)+pre[start]
        #        print(cur)
                start=end
            return cur

        for k in range(n-1):
            a=count(a)
        #print(a)
        return a
            
n=3

c=Solution()
import time
t1=time.time()

#计算几个数之和，下面就填几
c1=c.countAndSay( 4)
print(time.time()-t1)

print(c1)