【leetcode】Excel Sheet Column Title

 1 class Solution {
 2 public:
 3     string convertToTitle(int n) {
 4         if(n<1) return "";
 5         else
 6         {
 7             string ret="";
 8             while(n)
 9             {
10                 n--;
11                 char c=n%26+‘A‘;
12                 ret=c+ret;
13                 n/=26;
14             }
15               return ret;
16         }
17     }
18 };