题解 | #字符串最后一个单词的长度# 逆序遍历字符串

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        System.out.println(lengthOfLastWord(str));
    }

    private static int lengthOfLastWord(String str) {
        if (str == null || str.length() == 0) {
            return 0;
        }
        int count = 0;
        for (int i = str.length() - 1; i >= 0; i--) {
            if (str.charAt(i) == ' ') {
                return count;
            }
            count++;
        }
        return count;
    }
}