520. Detect Capital

class Solution {
    	public boolean detectCapitalUse(String word) {
		if (Character.isLowerCase(word.charAt(0))) {
			if (isAllLowerCase(word.substring(1)))
				return true;
		} else {
			if (isAllLowerCase(word.substring(1)) || isAllUpperCase(word.substring(1)))
				return true;
		}
		return false;
	}

	public boolean isAllLowerCase(String word) {
		for (int i = 0; i < word.length(); i++) {
			if (Character.isUpperCase(word.charAt(i)))
				return false;
		}
		return true;
	}

	public boolean isAllUpperCase(String word) {
		for (int i = 0; i < word.length(); i++) {
			if (!Character.isUpperCase(word.charAt(i)))
				return false;
		}
		return true;
	}
}