Length of Last Word

class Solution {
public:
    int getLastWordLength(string str) {
        int length = 0;
        int finalIndex = str.length() - 1;
        // Remove trailing spaces
        while (finalIndex >= 0 && str[finalIndex] == ' ') finalIndex--;
        // Count the characters of the last word
        while (finalIndex >= 0 && str[finalIndex] != ' ') {
            length++;
            finalIndex--;
        }
        return length;
    }
};

The provided C++ program defines a method getLastWordLength which calculates the length of the last word in a given string. This implementation avoids counting trailing spaces and iteratively counts the characters until it encounters a space, marking the beginning of the last word. The steps followed by the code are:

• Initialize length to 0, to keep track of the number of characters in the last word.
• Determine finalIndex as the position of the last character in the string.
• Strip any trailing spaces by decrementing finalIndex until a non-space character is found.
• Count backwards from finalIndex, incrementing length with each non-space character, until a space is encountered or finalIndex reaches the start of the string.
• Return the length as the size of the last word.

This method effectively handles strings with trailing spaces and returns the accurate length of the final word.

class Solution {
    public int lastWordLength(String input) {
        input = input.trim();
        return input.length() - input.lastIndexOf(" ") - 1;
    }
}

The provided Java function lastWordLength calculates the length of the last word in a given string. This function first removes any leading and trailing spaces from the input string using the trim() method. It then determines the length of the last word by subtracting the index of the last space from the total length of the string and adjusting by one to account for index offset. This function's approach is efficient because it avoids splitting the string into an array, focusing only on trimming and calculating based on the last space index, ensuring reduced time and space complexity especially for long strings.

int lastWordLength(char* string) {
    int length = 0;
    int i = strlen(string) - 1;
    while (i >= 0 && string[i] == ' ') i--;
    while (i >= 0 && string[i] != ' ') {
        length++;
        i--;
    }
    return length;
}

The provided C function named lastWordLength calculates the length of the last word in a given string. This function is useful for situations where you need to determine the number of characters in the last word of a sentence or any text.

Here's a breakdown of how the function works:

1. Initialize an integer length to 0. This variable will store the length of the last word.
2. Determine the position of the last character in the string that is not a space by initializing i to the last index of the string and decrementing it as long as the current character is a space.
3. Once non-space characters start (indicating the beginning of the last word), count these characters by incrementing the length until a space or the start of the string is encountered.

By the end of the function, length holds the number of characters in the last word of the string and is returned as the output. This logic ensures that trailing spaces are ignored and only the last word is considered for length calculation.

var getLastWordLength = function (str) {
    str = str.trim(); // trim the spaces at the end
    return str.length - str.lastIndexOf(" ") - 1;
};

The problem "Length of Last Word" aims to determine the length of the last word in a given string. The provided solution uses JavaScript to achieve this. The function getLastWordLength processes a string to find the length of its last word.

• Initialize the function getLastWordLength that takes a string str as its parameter.
• Trim any trailing spaces from the string using str.trim().
• Find the length of the last word by subtracting the position of the last space from the total length of the string. This is achieved using str.length - str.lastIndexOf(" ") - 1.
• Return the calculated length.

The function efficiently calculates the length of the last word by locating the last space and considering any trimmed spaces to ensure correctness. The approach is straightforward and effective for strings where words are separated by spaces.

class Solution:
    def getLastWordLength(self, input_string: str) -> int:
        return 0 if not input_string or input_string.isspace() else len(input_string.split()[-1])

The provided Python solution addresses the problem of determining the length of the last word in a given string. The function getLastWordLength in the Solution class takes a string as input and returns an integer representing the length of the last word. Here's an outline of how the function operates:

• First, you check if the input_string is either empty or contains only whitespace using conditions not input_string or input_string.isspace(). If either condition is true, the function returns 0.
• If the input string has content, input_string.split() splits the string into words based on whitespace.
• The last word in the list of words obtained from the split operation is accessed using [-1], and its length is computed and returned with len().

The solution effectively handles edge cases such as empty strings, strings consisting only of spaces, and strings with actual words. The use of split() ensures that any leading, trailing, or multiple spaces within the string do not affect the determination of the last word's length, making this solution robust and efficient for the given task.