38. Count and Say

The count-and-say sequence is the sequence of integers with the first five terms as following:

1.     12.     113.     214.     12115.     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: 1Output: "1"

Example 2:

Input: 4Output: "1211"

class Solution {    public String countAndSay(int n) {        if(n == 1){            return "1";        }        //递归调用，然后对字符串处理        String str = countAndSay(n-1) + "*";//为了str末尾的标记，方便循环读数        char[] c = str.toCharArray();        int count = 1;        String s = "";        for(int i = 0; i < c.length - 1;i++){            if(c[i] == c[i+1]){                count++;//计数增加            }else{                s = s + count + c[i];//上面的*标记这里方便统一处理                count = 1;//初始化            }        }        return s;    }}