License Key Formatting

class Solution {
public:
    string formatLicenseKey(string str, int n) {
        int validChars = 0;
        for (int j = 0; j < str.length(); j++) {
            if (str[j] != '-') {
                validChars++;
            }
        }
        int firstGroupSize = (validChars % n);
        if (firstGroupSize == 0) {
            firstGroupSize = n;
        }
        string result = "";
        int index = 0;
        int countCharacters = 0;
        
        while (index < str.length()) {
            if (countCharacters == firstGroupSize) {
                countCharacters = 0;
                break;
            }
            if (str[index] != '-') {
                countCharacters++;
                result.push_back(toupper(str[index]));
            }
            index++;
        }

        if (index >= str.length()) {
            return result;
        }
        
        result.push_back('-');
        
        while (index < str.length()) {
            if (str[index] != '-') {
                if (countCharacters == n) {
                    result.push_back('-');
                    countCharacters = 0;
                }
                result.push_back(toupper(str[index]));
                countCharacters++;
            }
            index++;
        }
        return result;
    }
};

The provided C++ function, formatLicenseKey, reformats a given string representing a license key. It focuses on accepting two parameters: str, the license key string to format, and n, determining the desired group length following the first segment. The function structures the key by grouping characters (excluding dashes) into segments of length specified. The entire process includes:

• Counting non-dash characters to decide the total number of valid characters in the input.
• Calculating the size of the initial group which could be smaller than n if validChars % n isn't zero; otherwise, it is n.
• Iterating through the string to first fill the initial group:
  • Characters are added to the result after converting them to uppercase, ensuring to exclude dashes.
  • Once the first group reaches its desired size, a dash is appended as a separator if not at the end of the string.
• Continue processing the rest of the string:
  • For subsequent characters, groups of n characters are formed, separated by a dash.
  • Each valid character, not being a dash, is converted to uppercase before appending to the result.

The key takeaway from the function is efficient management and transformation of the input string into the desired formatted output while ensuring correct groupings and handling of characters. The final result string is returned containing the formatted license key with specified groupings clearly separated by dashes.

class Formatter {
    public String formatLicenseKey(String input, int groupSize) {
        int alphaNumChars = 0;
        for (int index = 0; index < input.length(); index++) {
            if (input.charAt(index) != '-') {
                alphaNumChars++;
            }
        }
        int firstGroupLength = (alphaNumChars % groupSize);
        if (firstGroupLength == 0) {
            firstGroupLength = groupSize;
        }
        StringBuilder formattedKey = new StringBuilder();
        int currentIndex = 0;
        int currentCount = 0;
        
        while (currentIndex < input.length()) {
            if (currentCount == firstGroupLength) {
                currentCount = 0;
                break;
            }
            if (input.charAt(currentIndex) != '-') {
                currentCount++;
                formattedKey.append(Character.toUpperCase(input.charAt(currentIndex)));
            }
            currentIndex++;
        }
        if (currentIndex >= input.length()) {
            return formattedKey.toString();
        }
        formattedKey.append('-');
        while (currentIndex < input.length()) {
            if (input.charAt(currentIndex) != '-') {
                if (currentCount == groupSize) {
                    formattedKey.append('-');
                    currentCount = 0;
                }
                formattedKey.append(Character.toUpperCase(input.charAt(currentIndex)));
                currentCount++;
            }
            currentIndex++;
        }
        return formattedKey.toString();
    }
}

The provided Java code demonstrates a method to reformat a given license key string based on a specified group size. The code involves several steps:

• Define a method formatLicenseKey in the Formatter class that accepts a String input representing the unformatted license key and an int groupSize which determines how many characters each group in the formatted key should contain.
• Compute the number of alphanumeric characters in the input string by iterating over each character and counting characters other than dashes.
• Determine the length of the first group, which can differ from the subsequent groups if the total number of alphanumeric characters isn't a multiple of groupSize.
• Use a StringBuilder to construct the formatted license key.
• Start looping through the string, skipping dashes and converting characters to uppercase before adding them to the StringBuilder. Implement logic to add a dash after completing each group, ensuring the first group adheres to its computed unique size if applicable.
• Return the complete and formatted string after processing all characters in the input string.

This method effectively handles the formatting of license keys by grouping characters according to the specified groupSize, adjusting for cases where not all groups can be the same size and ensuring the use of uppercase letters, providing a standard format common in software license keys and other similar formats.

var formatLicenseKey = function(inputStr, groupSize) {
    let characterCount = 0;
    for (let index = 0; index < inputStr.length; index++) {
        if (inputStr.charAt(index) != '-') {
            characterCount++;
        }
    }
    let firstGroupLength = (characterCount % groupSize);
    
    if (firstGroupLength == 0) {
        firstGroupLength = groupSize;
    }
    
    let formattedKey = "";
    let index = 0;
    let currentCount = 0;
    
    while (index < inputStr.length) {
        if (currentCount == firstGroupLength) {
            currentCount = 0;
            break;
        }
        if (inputStr.charAt(index) != '-') {
            currentCount++;
            formattedKey += inputStr.charAt(index).toUpperCase();
        }
        index++;
    }
    
    if(index >= inputStr.length) {
        return formattedKey;
    }
    
    formattedKey += '-';
    
    while (index < inputStr.length) {
        if (inputStr.charAt(index) != '-') {
            if (currentCount == groupSize) {
                formattedKey += '-';
                currentCount = 0;
            }
            formattedKey += inputStr.charAt(index).toUpperCase();
            currentCount++;
        }
        index++;
    }
    return formattedKey;
}

The provided JavaScript function handles the formatting of a license key string according to specified group sizes. The function formatLicenseKey receives two parameters: inputStr, which is the unformatted license key as a string, and groupSize, an integer defining the size of each group of characters in the formatted key except possibly the first group.

Here’s a step-by-step explanation of the code:

1. Initialize characterCount to zero. Iterate through inputStr and count the alphanumeric characters, skipping dashes.

2. Calculate the length of the first group:

   • If the total count of characters modulo the groupSize is zero, then the first group's length is equal to groupSize.
   • Otherwise, it is the remainder of characterCount divided by groupSize.

3. Initialize variables for the formatted key (formattedKey), the index of the current character in inputStr, and a counter (currentCount) for characters added to the formattedKey.

4. Construct the first group of characters by converting each to uppercase and appending it to formattedKey until the length of the first group is reached.

5. If all characters are processed during the first group construction, return formattedKey.

6. Append a dash to separate the first group from the next.

7. Continue processing the rest of inputStr by appending each character (converted to uppercase) to formattedKey. Add dashes between groups when the count reaches the specified groupSize.

The function returns the formatted key after appending all the characters correctly grouped and in uppercase. This approach ensures that the initial part of the key may have a different grouping than the subsequent parts if characterCount isn't exactly divisible by groupSize. The format ensures all groups after the first adhere strictly to the groupSize specification.