LeetCode:Length of Last Word

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(const char *s) {
 4         if(s == NULL)return 0;
 5         int len = strlen(s), i, res = 0;
 6         for(i = len-1; i >= 0 && s[i] == ' '; i--);//从尾部开始找到第一个非空格字符
 7         for(; i >= 0 && s[i] != ' '; i--)res++;
 8         return res;
 9     }
10 };

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(const char *s) {
 4         if(s == NULL)return 0;
 5         int res = 0, cnt = 0;
 6         for(; *s != '\0'; s++)
 7         {
 8             if(*s == ' ')
 9             {
10                 if(cnt != 0)
11                     res = cnt;
12                 cnt = 0;
13             }
14             else cnt++;
15         }
16         return cnt == 0 ? res : cnt;
17     }
18 };