【leetcode】Count and Say

 1 class Solution {
 2 public:
 3     string count(const string &say)
 4     {
 5         stringstream ss;
 6         int count=0;
 7         char last=say[0];
 8 
 9         for(size_t i=0;i<=say.size();++i)
10         {
11             if(say[i]==last)
12             {
13                 ++count;
14             }else{
15                 ss<<count<<last;
16                 count=1;
17                 last=say[i];
18             }
19         }
20 
21         return ss.str();
22     }
23 
24 
25 
26     string countAndSay(int n) {
27         if(n==0) return string();
28 
29         string say="1";
30 
31         for(int i=1;i<n;i++)
32         {
33             say=count(say);
34         }
35 
36         return say;
37     }
38 };