Day4 Count and Say

LeetCode38.Count and Say

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 n^th 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"

意思是n=1返回1，然后后面的就是把前面的读出来，2就是11，3就是21，4就是1211，5就是111221……

思路就是从1开始递推，每次要记录当前所读到的相同字符的个数，然后把个数和该字符本身保存在临时字符串里。其实还是很简单的。