[CC150][1.5] Implement a method to perform basic string compression using the counts of repeated characters. For example, the string aabcccccaaa would become a2blc5a3. If the "compressed" string would not become smaller than the original string, your method should return the original string.

compressStr.java

public class compressStr {
	public static String compress(String s) {
		StringBuilder sb = new StringBuilder();
		int idx = 0;
		int l = s.length();
		boolean first = true;
		int count = 0;
		while (idx < l) {
			if (first) {
				sb.append(s.charAt(idx++));
				count = 1;
				first = false;
				if (idx == l)
					sb.append('1');
			}
			else {
				while (idx < l && s.charAt(idx) == s.charAt(idx - 1)) {
					idx++;
					count++;
				}
				sb.append(String.valueOf(count));
				first = true;
			}
		}
		String newStr =  sb.toString();
		return (newStr.length() < l) ? newStr : s;
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println(compressStr.compress("aaaaaaaaaaaaaaaaaaaaaaaa"));
		System.out.println(compressStr.compress("aaaaabbbbb      "));
		System.out.println(compressStr.compress(""));
		System.out.println(compressStr.compress("abc"));
		System.out.println(compressStr.compress("aaaabbbbc"));
		System.out.println(compressStr.compress("呵呵呵呵呵呵"));
		System.out.println(compressStr.compress("呵呵"));
		System.out.println(compressStr.compress("呵"));
	}

}