Length Of Last Word

Problem

https://leetcode.com/problems/length-of-last-word/

Given a string s consisting of words and spaces, return the length of the last word in the string.

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

Example 1:

Input: s = "Hello World"
Output: 5
Explanation: The last word is "World" with length 5.

Example 2:

Input: s = "   fly me   to   the moon  "
Output: 4
Explanation: The last word is "moon" with length 4.

Example 3:

Input: s = "luffy is still joyboy"
Output: 6
Explanation: The last word is "joyboy" with length 6.

Constraints:

• 1 <= s.length <= 10:sup:`4`

• s consists of only English letters and spaces ' '.

• There will be at least one word in s.

Pattern

String

Solution

Strip all the whitespace from the end of the string, then split the string by spaces. The last element in the list is the last word in the string.

Code

def lengthOfLastWord(s: str) -> int:
    """Finds the length of the last word in a string.
    """
    return len(s.strip().split(' ')[-1])

Test

>>> from length_of_last_word__approach_1 import lengthOfLastWord
>>> lengthOfLastWord('Hello World')
5
>>> lengthOfLastWord('   fly me   to   the moon  ')
4
>>> lengthOfLastWord('luffy is still joyboy')
6

Complexity

\(n\) is the length of the input string.

Time: \(O(n)\) — strip and split

Auxiliary Space: \(O(1)\)

length_of_last_word__approach_1.lengthOfLastWord(s: str) → int

Finds the length of the last word in a string.