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

.

public class Solution {
public int lengthOfLastWord(String s) {
if(s=="")
return 0;
int len=s.length();
int i=len-1;
while(i>=0&&s.charAt(i)==' '){
--i;
}
if(i<0)
return 0;
int n=0;
while(i>=0&&s.charAt(i)!=' '){
++n;
--i;
}
return n;
}
}

WONDERFUL SOLUTION
public int lengthOfLastWord(String s) {
s = s.trim();
int lastIndex = s.lastIndexOf(' ') + 1;
return s.length() - lastIndex;
}