Leetcode 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.

思路：由后向前遍历，先去掉末尾的空格，然后截取最后一个word。

代码：

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(string s) {
 4         int i=s.size()-1,j;
 5         while(i>=0&&s[i]==‘ ‘) i--;
 6         j=i;
 7         while(i>=0&&s[i]!=‘ ‘) i--;
 8         return j-i;
 9     }
10 };