package leetcode_301To600;

/**
 * 本代码来自 Cspiration，由 @Cspiration 提供
 * 题目来源：http://leetcode.com
 * - Cspiration 致力于在 CS 领域内帮助中国人找到工作，让更多海外国人受益
 * - 现有课程：Leetcode Java 版本视频讲解（1-900题）（上）（中）（下）三部
 * - 算法基础知识（上）（下）两部；题型技巧讲解（上）（下）两部
 * - 节省刷题时间，效率提高2-3倍，初学者轻松一天10题，入门者轻松一天20题
 * - 讲师：Edward Shi
 * - 官方网站：https://cspiration.com
 * - 版权所有，转发请注明出处
 */
public class _520_DetectCapital {

    /**
     * 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:

     All letters in this word are capitals, like "USA".
     All letters in this word are not capitals, like "leetcode".
     Only the first letter in this word is capital if it has more than one letter, like "Google".
     Otherwise, we define that this word doesn't use capitals in a right way.
     Example 1:

     Input: "USA"
     Output: True
     Example 2:

     Input: "FlaG"
     Output: False

     time : O(n)
     space : O(1)
     * @param word
     * @return
     */

    public boolean detectCapitalUse(String word) {
        int numUpper = 0;
        for (int i = 0; i < word.length(); i++) {
             if (Character.isUpperCase(word.charAt(i))) {
                 numUpper++;
             }
        }

        if (numUpper == 1) {
            return Character.isUpperCase(word.charAt(0));
        }

        return numUpper == 0 || numUpper == word.length();
    }

}