/**

* 420. Count and Say

* 中文English

* The count-and-say sequence is the sequence of integers beginning as follows:

*

* 1, 11, 21, 1211, 111221, ...

*

* 1 is read off as "one 1" or 11.

*

* 11 is read off as "two 1s" or 21.

*

* 21 is read off as "one 2, then one 1" or 1211.

*

* Given an integer n, generate the nth sequence.

*

* Example

* Example 1:

*

* Input: 1

* Output: "1"

* Example 2:

*

* Input: 5

* Output: "111221"

* Notice

* The sequence of integers will be represented as a string.

*/

public class CountAndSay {

public static void main(String args[]){

System.out.println("Hello Count And Say");

System.out.println(countAndSay(11));

}

public static String countAndSay(int n){

StringBuffer outputBuf = new StringBuffer();

String output;

if(n == 1){

output = "1";

return output;

}else if(n == 2){

output = "11";

return output;

}else{

String str = countAndSay(n-1);

char []charArr = str.toCharArray();

int number = charArr[0] - 48;

int count = 1;

int i = 1;

while(i<charArr.length){

if(charArr[i] == charArr[i-1]){ // if current value was the same with the last one

count ++;

}else{

outputBuf.append(Integer.toString(count));

outputBuf.append(Integer.toString(number));

number = charArr[i] -48;

count = 1;

}

i++;

}

outputBuf.append(Integer.toString(count));

outputBuf.append(Integer.toString(number));

output = outputBuf.toString();

return output;

}

}

}