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.

Given s = "Hello World",

return 5 as length("World") = 5.

Please make sure you try to solve this problem without using library functions. Make sure you only traverse the string once.


Solution:

Time: O(n)
Space: O(1)

public class Solution {
    // DO NOT MODIFY THE LIST. IT IS READ ONLY
    public int lengthOfLastWord(final String A) {
        int length = 0;
        boolean isWord = false;
        
        for (int i = A.length() - 1; i >= 0; i --) {
            char c = A.charAt(i);
            if (c == ' ') {
                if (isWord) {
                    break;
                }
            } else {
                isWord = true;
                length ++;
            }
        }
        
        return length;
    }
}