Leetcode 38: Count and Say

class Solution {
public:
    string countAndSay(int n) {
        if(n == 1)
            return "1";
        else if (n == 2)
            return "11";
        else 
        {
            string result_pre = countAndSay(n-1);
            string result = "";
            char temp = result_pre[0];
            int count_pre = 1;
            for(int i=1; i<result_pre.length();i++)
            {
                if(temp == result_pre[i])
                    count_pre++;
                else
                {
                    result = result +  char(count_pre + '0') + temp;
                    count_pre = 1;                    
                }
                temp = result_pre[i];
            }
            result = result + char(count_pre + '0') + result_pre[result_pre.length()-1];
            return result;
        }
    }
};