Description:
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.
Examples:
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.Solution in Python:
To solve this problem, we need to find the length of the last word in a given string sss. The string sss consists of words separated by spaces. The key steps to solve this problem are:
- Trim any trailing spaces from the string.
- Split the string into a list of words.
- Return the length of the last word in the list.
Here is a step-by-step breakdown of the solution:
- Trim Trailing Spaces: Using the
strip()method, we can remove any leading or trailing spaces from the string. This ensures that any spaces at the end do not affect our word detection. - Split the String: Use the
split()method to divide the string into a list of words. By default,split()divides the string by any whitespace and removes any empty strings from the result. - Find the Last Word: The last word in the list will be the last element of the list.
- Return the Length: Use the
len()function to find and return the length of the last word.
Python
class Solution:
def lengthOfLastWord(self, s: str) -> int:
# Step 1: Trim trailing and leading spaces
s = s.strip()
# Step 2: Split the string into words
words = s.split()
# Step 3: Get the last word in the list
last_word = words[-1]
# Step 4: Return the length of the last word
return len(last_word)
# Examples to test the function
solution = Solution()
print(solution.lengthOfLastWord("Hello World")) # Output: 5
print(solution.lengthOfLastWord(" fly me to the moon ")) # Output: 4
print(solution.lengthOfLastWord("luffy is still joyboy")) # Output: 6Explanation:
strip(): This method removes any leading and trailing whitespace characters from the string.split(): This method splits the string into a list of words based on whitespace. For example,"Hello World"becomes["Hello", "World"].words[-1]: This accesses the last element of the listwords.len(last_word): This computes the length of the last word in the list.
Solution in Javascript:
JavaScript
/**
* @param {string} s
* @return {number}
*/
var lengthOfLastWord = function(s) {
// Step 1: Trim leading and trailing spaces
s = s.trim();
// Step 2: Split the string into words
let words = s.split(/\s+/);
// Step 3: Get the last word in the list
let lastWord = words[words.length - 1];
// Step 4: Return the length of the last word
return lastWord.length;
};
// Examples to test the function
console.log(lengthOfLastWord("Hello World")); // Output: 5
console.log(lengthOfLastWord(" fly me to the moon ")); // Output: 4
console.log(lengthOfLastWord("luffy is still joyboy")); // Output: 6Solution in Java:
Java
class Solution {
public int lengthOfLastWord(String s) {
// Step 1: Trim leading and trailing spaces
s = s.trim();
// Step 2: Split the string into words
String[] words = s.split("\\s+");
// Step 3: Get the last word in the list
String lastWord = words[words.length - 1];
// Step 4: Return the length of the last word
return lastWord.length();
}
// Main method for testing the function
public static void main(String[] args) {
Solution solution = new Solution();
System.out.println(solution.lengthOfLastWord("Hello World")); // Output: 5
System.out.println(solution.lengthOfLastWord(" fly me to the moon ")); // Output: 4
System.out.println(solution.lengthOfLastWord("luffy is still joyboy")); // Output: 6
}
}Solution in C#:
C#
public class Solution {
public int LengthOfLastWord(string s) {
// Step 1: Trim leading and trailing spaces
s = s.Trim();
// Step 2: Split the string into words
string[] words = s.Split(new char[] {' '}, StringSplitOptions.RemoveEmptyEntries);
// Step 3: Get the last word in the list
string lastWord = words[words.Length - 1];
// Step 4: Return the length of the last word
return lastWord.Length;
}
}