我的code，就是阅读理解，但是比较完备，tolerant String可能不规范的情况。

public boolean detectCapitalUse(String word) {		if (word == null || word.length() <= 1) {			return true;		}		for (int i = 0; i < word.length(); i++) {			//首字母小写			if (isLowerCaseLetter(word.charAt(0))) {				if (!isLowerCaseLetter(word.charAt(i))) {					return false;				}			}			//首字母大写			else if (isUpperCaseLetter(word.charAt(0))) {				if (isUpperCaseLetter(word.charAt(1))) {					if (i > 1 && !isUpperCaseLetter(word.charAt(i))) {						return false;					}				} else if (isLowerCaseLetter(word.charAt(1))) {					if (i > 1 && !isLowerCaseLetter(word.charAt(i))) {						return false;					}				}			} else {				return false;			}		}		return true;	}	private boolean isLowerCaseLetter(char c) {		return c <= 'z' && c >= 'a';	}	private boolean isUpperCaseLetter(char c) {		return c <= 'Z' && c >= 'A';	}复制代码

简洁的代码：

public class Solution {    public boolean detectCapitalUse(String word) {        int cnt = 0;        for(char c: word.toCharArray()) if('Z' - c >= 0) cnt++;        return ((cnt==0 || cnt==word.length()) || (cnt==1 && 'Z' - word.charAt(0)>=0));    }}复制代码