字符串中最后一个单词的长度 Length of Last Word

题目源自于leetcode。简单题。

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.

思路：从右向左。先排除字符串末尾的空格。再找到单词的长度。

代码：

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