public void partition(char[] str) {
		int gt = -1;
		char pivot = str[0];
		// System.out.println(s[1]);
		for (int i = 1; i < str.length; i++) {
			if (str[i] > pivot) {
				gt = gt > 0 ? gt : i;
			} else {
				if (gt >= 0) {
					char t = str[i];
					str[i] = str[gt];
					str[gt] = t;
					gt++;
				}
			}
		}
	}