CountAndSay.java

public class Solution {
    public String countAndSay(int n) {
         if (n == 1)     return "1"; 
    if (n == 2)     return "11"; 
  
  
      
  
    String str = "11";  
    for (int i = 3; i <= n; i++) 
    { 
        // In below for loop, previous  
        // character is processed in  
        // current iteration. That is 
        // why a dummy character is  
        // added to make sure that loop 
        // runs one extra iteration. 
        str += '$'; 
        int len = str.length(); 
  
        int cnt = 1; // Initialize count  
                     // of matching chars 
        String tmp = ""; // Initialize i'th  
                         // term in series 
        char []arr = str.toCharArray(); 
          
        // Process previous term 
        // to find the next term 
        for (int j = 1; j < len; j++) 
        { 
            // If current character 
            // does't match 
            if (arr[j] != arr[j - 1]) 
            { 
                // Append count of  
                // str[j-1] to temp 
                tmp += cnt + 0; 
  
                // Append str[j-1] 
                tmp += arr[j - 1]; 
  
                // Reset count 
                cnt = 1; 
            } 
  
            // If matches, then increment  
            // count of matching characters 
            else cnt++; 
        } 
  
        // Update str 
        str = tmp; 
    } 
  
    return str;
    }
}