<LeetCode><Easy> 38 Count and Say

The count-and-say sequence is the sequence of integers beginning as follows:

1, 11, 21, 1211, 111221, ...

1

 is read off as 

"one
1"

 or 

11

.

11

 is read off as 

"two
1s"

 or 

21

.

21

 is read off as 

"one
2

, then 

one 1"

 or 

1211

.

Given an integer n, generate the nth sequence.

Note: The sequence of integers will be represented as a string.

#Python2  68ms

class Solution(object):
def countAndSay(self, n):
"""
:type n: int
:rtype: str
"""
def H(x):
rList,count,tmp="",0,x[0]
for i in range(len(x)):
if x[i] == tmp:
count+=1
else:
rList,tmp,count=rList+str(count)+tmp,x[i],1
return rList+str(count)+tmp
x='1'
for i in range(n-1):
x=H(x)
return x