题目：
题解：
python
class Solution:
def countAndSay(self, n: int) -> str:
prev = "1"
for i in range(n-1):
curr = ""
pos = 0
start = 0
while pos < len(prev):
while pos < len(prev) and prev[pos] == prev[start]:
pos += 1
curr += str(pos - start) + prev[start]
start = pos
prev = curr
return prev