[Leetcode 58, easy] Length of Last Word

Problem:

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.

Analysis:

Solutions:

C++:

    int lengthOfLastWord(string s) {        if(s.size() == 0)            return 0;                    int length = 0;        int size = s.size();        for(int i = size - 1; i >= 0;) {            if(s[i] != ' ') {                int j = i;                for(; j >= 0; --j) {                    if(s[j] == ' ')                        break;                    ++length;                }                break;            } else                --i;        }                return length;    }

Java:

Python: