【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.

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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：

 1 public class Solution {

 2     public int lengthOfLastWord(String s) {

 3         int answer = 0;

 4         int i = s.length()-1;

 5         while(i >= 0 && s.charAt(i) == ' ')

 6             i--;

 7         for(;i >= 0;i--){

 8             if(s.charAt(i) != ' ')

 9                 answer++;

10             else {

11                 break;

12             }

13         }

14        

15         return answer;

16     }

17 }

特别要注意第5行while循环时候要判断边界。