lastWordLength.md

Description: Given an input string str which consists of words and spaces, return the length of the last word in the string.

Note: A word is considered as a maximal substring of non-space characters.

Examples

Example 1:
Input: "Welcome to DSA"
Output: 3

Example 2:
Input: " My pet is fluffy "
Output: 6

Example 3:
Input: " "
Output: 0

Algorithm

This problem is efficiently solved by traversing the string from the end:

1. Start from the last character of the string.
2. Skip any trailing spaces.
3. Count the length of the last word by iterating backwards until a space or the start of the string is reached.
4. Return the length.

Complexity

• Time Complexity: O(n), where n is the length of the string. This is because we may need to iterate entire string incase of single word string(worst case scenario).
• Space Complexity: O(1), as only a few variables are used.