[LeetCode] 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

.

Solution:

class Solution {
public:
int lengthOfLastWord(const char *s) {
int len = 0;
while(s[len] != '\0') len++;
if(len == 0) return 0;

int start = len - 1, end = len - 1;
while(end >= 0 && s[end] == ' ') end--;
if(end < 0) return 0;
start = end - 1;
while(start >= 0 && s[start] != ' ') start--;

return end - start;
}
};