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.

 int lengthOfLastWord(const char *s) {
 int l = strlen(s);
        if(l <= 0)
  return 0;
 // run from the reverse
 // get the first non empty character index;
 int i  = l - 1;
 for(i = l - 1; i >= 0; i--)
 {
  if(s[i] != ' ')
   break;
        }

 int j =0 ;
 for(j = i; j >= 0; j--)
 {
   if(s[j] == ' ')
    break;
 }

 return i - j;
 }