lengthOfLastWord.py

"""
Given a string s consists of some words separated by spaces, return the length of the last word in the string.
If the last word does not exist, return 0.

A word is a maximal substring consisting of non-space characters only.

Input: s = "Hello World"
Output: 5

Input: s = " "
Output: 0

Input: s = "a b    "
Output: 1
"""


class Solution:
    def lengthOfLastWord(self, s: str) -> int:
        result = s.split(" ")
        n = len(result)
        for i in range(n - 1, -1, -1):
            if len(result[i]) != 0:
                return len(result[i])
        return 0

    # Came across this solution that eliminates the need for the loop in my first implementation.
    # It basically strips all the trailing spaces so we needn't worry about handling an input like "a b    "
    def lengthOfLastWord2(self, s: str) -> int:
        s = s.strip().split(" ")
        if len(s) == 0:
            return 0
        else:
            return len(s[-1])