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QuestionInformation Technology

Write a java code using the luhn checksum validation algorithm to check whether a credit card is valid or fake Example of execution of the algorithm: Suppose you want to check that your credit card number is valid. You credit card number is 8273123273510569 . Let's see how to check it: | 0 | 2 | 7 | 3 | 1 | 2 | 3 | 2 | 7 | 3 | 5 | 1 | 0 | 5 | 6 | 9 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | | | | | | | | | | | | | | | | | First, you are going to double every other number, starting with the first number (here, it is number 8): | 0x^2 | 2 | 7x^2 | 3 | 1x^2 | 2 | 3x^2 | 2 | 7x^2 | 3 | 5x^2 | 1 | 0x^2 | 5 | 6x^2 | 9 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | | | | | | | | | | | | | | | | | And you obtain: | 16 | 2 | 14 | 3 | 2 | 2 | 6 | 2 | 14 | 3 | 10 | 1 | 0 | 5 | 12 | 9 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | | | | | | | | | | | | | | | | | But we do not want double digits, so for every number that now has double digits, we add these digits: | 1 + 6 | 2 | 1 + 4 | 3 | 3 | 2 | 6 | 2 | 1 + 4 | 3 | 1 + 8 | 1 | 0 | 5 | 1 + 2 | 9 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | | | | | | | | | | | | | | | | | And we obtain: | 7 | 2 | 5 | 3 | 2 | 2 | 6 | 2 | 5 | 3 | 1 | 1 | 0 | 5 | 3 | 9 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | | | | | | | | | | | | | | | | | Now we add all of these numbers: $7 + 2 + 5 + 3 + 2 + 2 + 6 + 2 + 5 + 3 + 1 + 1 + 0 + 5 + 3 + 9 = 1$ 56 is not a multiple of 10 , so the credit card number was a fake.

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Step 1:
Here's a Java implementation of the Luhn algorithm for credit card validation:

```java public class CreditCardValidator { public static boolean isValidCreditCard(String cardNumber) { // Step 1: Remove any spaces or hyphens from the card number cardNumber = cardNumber.replaceAll("[\s-]", ""); // Step 2: Check if the card number contains only digits if (!cardNumber.matches("\d+")) { return false; } // Step 3: Convert the card number to an array of digits int[] digits = new int[cardNumber.length()]; for (int i = 0; i < cardNumber.length(); i++) { digits[i] = Character.getNumericValue(cardNumber.charAt(cardNumber.length() - 1 - i)); } // Step 4: Apply Luhn algorithm int sum = 0; for (int i = 0; i < digits.length; i++) { int digit = digits[i]; // Double every second digit from right to left if (i % 2 == 1) { digit *= 2; // If doubled digit is two digits, sum its digits if (digit > 9) { digit = digit / 10 + digit % 10; } } sum += digit; } // Step 5: Check if sum is divisible by 10 return (sum % 10 == 0); } public static void main(String[] args) { // Test cases String validCard = "4111111111111111"; String invalidCard = "8273123273510569"; System.out.println("Valid Card: " + isValidCreditCard(validCard)); System.out.println("Invalid Card: " + isValidCreditCard(invalidCard)); } } ``` Let's break down the Luhn algorithm implementation:

Step 2:
: Preprocessing

- Remove any spaces or hyphens from the card number - Ensure the card number contains only digits

Step 3:
: Digit Processing

- Convert the card number to an array of digits - Start from the rightmost digit (least significant digit)

Step 4:
: Luhn Algorithm Application

- Iterate through the digits - Double every second digit from right to left - If the doubled digit is two digits, sum its digits - Accumulate the sum of processed digits

Step 5:
: Validation

- Check if the total sum is divisible by 10 - If divisible by 10, the card number is valid - If not divisible by 10, the card number is invalid Key Points: - Works for various card types (Visa, MasterCard, etc.) - Handles different card number formats - Simple and efficient validation method Example Execution: - Valid Card (4111111111111111): Returns true - Invalid Card (8273123273510569): Returns false The algorithm follows the exact steps demonstrated in the example:

Step 6:

Double every second digit

Step 7:

Sum digits of doubled numbers

Step 8:

Add all processed digits

Step 9:

Space Complexity: $$O(n)$$ to store the digit array

Check divisibility by 10

Final Answer

Space Complexity: O(n) to store the digit array

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Q
QuestionInformation Technology

Answer

Full Solution Locked

Step 1:
Here's a Java implementation of the Luhn algorithm for credit card validation:

Step 2:
: Preprocessing

Step 3:
: Digit Processing

Step 4:
: Luhn Algorithm Application

Step 5:
: Validation

Step 6:

Step 7:

Step 8:

Step 9:

Final Answer

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QQuestionInformation Technology

AnswerHelpful

Full Solution Locked

Step 1:Here's a Java implementation of the Luhn algorithm for credit card validation:

Step 2:: Preprocessing

Step 3:: Digit Processing

Step 4:: Luhn Algorithm Application

Step 5:: Validation

Step 6:

Step 7:

Step 8:

Step 9:

Final Answer

Need Help with Homework?

Related Questions

Q
QuestionInformation Technology

Answer

Step 1:
Here's a Java implementation of the Luhn algorithm for credit card validation:

Step 2:
: Preprocessing

Step 3:
: Digit Processing

Step 4:
: Luhn Algorithm Application

Step 5:
: Validation