LeetCode Length of Last Word 字符串

思想：

只有字母、空格、'\0'三种类型的字符。

class Solution {public:    int lengthOfLastWord(const char *s) {        if(s == NULL) return 0;        int length = 0;        while(*s) {            if(*s++!=' ') {                length++;            }else if(*s && *s!=' ') {                length = 0;            }        }        return length;    }};

class Solution {public:    int lengthOfLastWord(string s) {        int length = 0;        for(int i = s.length() - 1; i >= 0; --i) {            if(s[i] != ' ')  {                length++;            }else if(length != 0){                return length;            }        }        return length;    }};