Credit Card Validation Application

Write a c program that reads a credit card number from the user. The c program will display: � Valid: if the credit card is valid � Invalid: if the credit card is invalid The program will also display the type of the credit card according to the starting digit (1st digit from left to right). The credit card number must start with: � 3 for American Express � 4 for Visa � 5 for MasterCard � 6 for Discover Card

The total number of digits of a credit card number must be between 13 to 16 digits. In addition, your program should validate credit card numbers according to Luhn Rule that is basically can be described as follows (as an illustration, the rules will be applied to the credit card number 4388576018402626):

1. Double every even digit from right to left. If the doubling results in two digits number, sum the digits to get a single digit number.

2. Compute the sum of single digit numbers obtained from step 1 above: Sum of even single-digits = 4 + 4 + 8 + 2 + 3 + 1 + 7 + 8 = 37

3. Compute the sum of every odd digit from right to left: Sum of odd digits = 6 + 6 + 0 + 8 + 0 + 7 + 8 + 3 = 38

4. Compute the sum of the results from step 2 and step 3: Total sum = 37 + 38 = 75

5. If the total sum from step 4 is divisible by 10, the card number is valid. Otherwise it�s not valid.

Is 75 divisible by 10 (without remainder)? No, the card number in this example is Invalid.

Output Samples:

Enter A Credit Card Number: 5278576018410707 (ENTER) Credit Card Belongs To MasterCard The Credit Card Number is VALID

Enter A Credit Card Number: 4388576018402626 (ENTER) The card Number is INVALID

Enter A Credit Card Number: 601195764182 (ENTER) Number of digits: [ 12 ] The card Number is INVALID

Enter A Credit Card Number: 43885760184026261 (ENTER) Number of digits: [ 17 ] The card Number is INVALID

Enter A Credit Card Number: 373800410401774 (ENTER) Credit Card Belongs To American Express The Credit Card Number is VALID

Note1: you have to use user-defined functions wherever they are needed.

Note2: The credit card number is usually (ex. 438857601840262) larger than what int variable can hold. To solve this problem:

For windows users (C-free IDE), you can use long long int data type as shown in the following example: long long int cardNumber; printf("Enter A Credit Card Number: "); scanf("%lld",&cardNumber);

For Mac users (Xcode IDE), you can use long data type as shown in the following example: long cardNumber; printf("Enter A Credit Card Number: "); scanf("%ld",&cardNumber);

& thank you very much {}.