38. Count and Say（C++）

 1 class Solution {
 2 public:
 3     string countAndSay(int n) {
 4         if(n==0) return "";
 5         string res="1";
 6         while(--n){
 7             string tmp="";
 8             for(int i=0;i<res.size();i++){
 9                 int count=1;
10                 while(res[i]==res[i+1]&&i+1<res.size()){
11                     count++;i++;
12                 }
13                 tmp+=to_string(count)+res[i];
14             }
15             res=tmp;
16         }
17         return res;
18     }
19 };