Given a string s consists of upper/lower-case alphabets and empty space characters ’ ‘, return the length of last word in the string.
If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

For example,
Given s = “Hello World”,
return 5.

求一字符串中最后一个单词中的长度，很简单，只要注意不要访问越界就哦啦~贴代码：

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        int len = strlen(s);
        if (!len)
            return 0;
        int i = len - 1;
        while (i>=0&&s[i] == ' '){
            i--;
        }
        int count = 0;
        while (i>=0&&s[i] != ' '){
            count++;
            i--;
        }
        return count;
    }
};