【leetcode刷题笔记】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.

---

题解：简单题，从后往前遍历就可以了。注意边界问题。

代码如下：

 public class Solution {
     public int lengthOfLastWord(String s) {
         int answer = 0;
         int i = s.length()-1;
         while(i >= 0 && s.charAt(i) == ' ')
             i--;
         for(;i >= 0;i--){
             if(s.charAt(i) != ' ')
                 answer++;
             else {
                 break;
             }
         }

         return answer;
     }
 }

特别要注意第5行while循环时候要判断边界。