*Count and Say

 1 public class Solution {
 2     public String countAndSay(int n) 
 3     {
 4         String oldString = "1";
 5         while(--n>0)
 6         {
 7             StringBuilder sb = new StringBuilder();
 8             char[] oldChar = oldString.toCharArray();
 9             for(int i=0;i<oldChar.length;i++)
10             {
11                 int count =1;
12                 while((i+1)<oldChar.length&&oldChar[i]==oldChar[i+1])
13                 {
14                     count++;
15                     i++;
16                 }
17                 sb.append(String.valueOf(count)+String.valueOf(oldChar[i]));
18                 
19             }
20             oldString = sb.toString();
21             
22         }
23         
24         return oldString;
25     }
26 }