LeetCode 38 Count and Say（字符串规律输出）

package leetcode_50;

/***
*
* @author pengfei_zheng
* 按照规律进行求解字符串
*/
public class Solution38 {
public static String countAndSay(int n) {
if(n<=0) {
return "";
}
String s="1";
int times = 1;
while(times<n){
s = getSay(s);
times++;
}
return s;
}
private static String getSay(String s) {
int count =0;
StringBuilder str = new StringBuilder("");
for(int i = 0; i<s.length(); i++){
//first to add in order to prevent thinking about the index
count ++;
//not reach the end of s and next item is not equal to the pre item
if ((i< s.length()-1) && (s.charAt(i) != s.charAt(i + 1))) {
str = str.append(count).append(s.charAt(i));//rebuild the str
count = 0;//reset count to zero
}
else if ((i == s.length()-1)) {//meet the end of s
str = str.append(count).append(s.charAt(i));
}
}
return str.toString();
}
public static void main(String[]args){
String s = countAndSay(2);
System.out.println(s);
}
}