// Given a word, you need to judge whether the usage of capitals in it is right or not.

// We define the usage of capitals in a word to be right when one of the following cases holds:

// 1. All letters in this word are capitals, like "USA".

// 2. All letters in this word are not capitals, like "leetcode".

// 3. Only the first letter in this word is capital, like "Google".

// Otherwise, we define that this word doesn't use capitals in a right way.

// See: https://leetcode.com/problems/detect-capital/submissions/

// See: https://leetcode.com/explore/featured/card/august-leetcoding-challenge/549/week-1-august-1st-august-7th/3409/

package leetcode.string;

public class DetectCapital {

// TODO: Try the easier solution with a regex.

public boolean detectCapitalUse(String word) {

if (word.length() == 1)

return true;

boolean upper0 = Character.isUpperCase(word.charAt(0));

boolean upper1 = Character.isUpperCase(word.charAt(1));

for (int i = 1; i < word.length() - 1; i++) {

if (Character.isUpperCase(word.charAt(i)) && Character.isLowerCase(word.charAt(i + 1))

|| Character.isLowerCase(word.charAt(i))

&& Character.isUpperCase(word.charAt(i + 1)))

return false;

}

return upper0 && upper1 || upper0 && !upper1 || !upper0 && !upper1;

}

public static void main(String[] args) {

DetectCapital sln = new DetectCapital();

System.out.println(sln.detectCapitalUse("USA")); // true

System.out.println(sln.detectCapitalUse("FlaG")); // false

System.out.println(sln.detectCapitalUse("aAAA")); // false

System.out.println(sln.detectCapitalUse("Google")); // false

System.out.println(sln.detectCapitalUse("ggg")); // false

}

}