leetcode 58. Length of Last Word

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.
Example:

Input: "Hello World"
Output: 5

class Solution {
public:
int lengthOfLastWord(string s)
{
for (int i = s.size() - 1; i >= 0; i--)
{
if (s[i] != ' ') //i确定最后一个单词的最后一个字母
{
for(int j = i; j >= 0; j--) //确定最后一个单词的第一个字母
{
if (s[j] == ' ')
{
return i - j;
}
}
return i + 1;
}
}
return 0;
}
};