# leetcode: 38. Count and Say

## Problem

```# The count-and-say sequence is the sequence of integers
# with the first five terms as following:
#
# 1.     1
# 2.     11
# 3.     21
# 4.     1211
# 5.     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 term of the count-and-say sequence.
#
# Note: Each term of the sequence of integers will be represented as a string.
#
# Example 1:
#
# Input: 1
# Output: "1"
#
# Example 2:
#
# Input: 4
# Output: "1211"```

## AC

```class Solution():
def countAndSay(self, n):
if not n:
return ''
res = "1"
for _ in range(n-1):
tmp, count = '', 1
for i in range(1, len(res)):
if res[i] == res[i-1]:
count += 1
else:
tmp += (str(count) + str(res[i-1]))
count = 1
tmp += (str(count) + str(res[-1]))
res = tmp
return res

if __name__ == "__main__":
assert Solution().countAndSay(1) == '1'
assert Solution().countAndSay(2) == '11'
assert Solution().countAndSay(3) == '21'
assert Solution().countAndSay(4) == '1211'
assert Solution().countAndSay(5) == '111221'
assert Solution().countAndSay(6) == '312211'```

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