58. Length of Last Word

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.

 

 求最后一个单词的长度,要去掉最后多余的空格

 

C++(3ms):

 

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(string s) {
 4         int len = s.length() ;
 5         int res = 0 ;
 6         int tail = len-1 ;
 7         while(tail >= 0 && s[tail] == ' ')
 8             tail-- ;
 9         while(tail >= 0 && s[tail] != ' '){
10             res++ ;
11             tail-- ;
12         }
13         return res ;
14     }
15 };

 

 

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(string s) {
 4         int len = s.length() ;
 5         int res = 0 ;
 6         int i ;
 7         for (i = len-1 ; i >= 0  ; i--){
 8             if (s[i] != ' ')
 9                 break ;
10         }
11         for(; i >= 0  ; i--){
12             if (s[i] == ' ')
13                 break ;
14             else
15                 res++ ;
16         }
17         return res ;
18     }
19 };

 

posted @ 2017-10-15 13:38  __Meng  阅读(146)  评论(0编辑  收藏  举报