LeetCode 58 Length of Last Word

题目：

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.

题目链接

题意：

给一个字符串，由字母和空格组成，问最后一个单词的长度，一个字母也可为一个单词。

从后向前找第一个字母，之后再找到连续字母的长度，即为所要求的长度。

代码如下；

class Solution {
public:
    int lengthOfLastWord(string s) {
        int cur = s.length() - 1;
        while (cur >= 0 && !isalpha(s[cur])) {
            cur --;
        }
        int len = 0;
        while (cur - len >= 0 && isalpha(s[cur - len])) {
            len ++;
        }
        return len;
    }
};