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, for s = "Hello World", return 5.

Approach: The idea is to start traversing from the right (ignoring the right spaces if any) and continue till a space is not found. 

class Solution {
public:
    int lengthOfLastWord(string s) {
        int len = s.length();
        int i = len - 1, j = 0;
        while(s[i] == ' '){
            i--;
        }
        while(i >=0 && ((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z'))){
            i--;
            j++;
        }
        return j;
    }
};

Here is the link to the ideone solution : http://ideone.com/pYNIG9