【LeetCode】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.

class Solution {
public:
    int lengthOfLastWord(string s) {
        int n=s.size()-1;
        while(n>=0&&s.at(n)&&s.at(n)==' ')n--;
        int i=0;
        
        for(;n>=0&&s.at(n)&&s.at(n)!=' ';n--,i++);
        return i;
    }
};