C++ Please explain each step and what it does.

Problem Statement Write a program that performs Credit Card Number Check. Your program should repeatedly ask the user to input an 8-digit number to check if it is valid, until the user enters 1 to quit. (Please note that for simplicity, now you can assume the user will always enter 8-digit numbers to check except for quitting the program with 1. In the coming week, we will learn how to handle the user input validation). Please note that this Lab assignment is from the Programming Project 4.22.21 of the ZyBook. Your program will implement the following algorithm: The last digit of a credit card number is the check digit, which protects against transactions errors such as an error in a single digit or switching two digits. The following method is for numbers with 8 digits: - Starting from the rightmost digit, form the sum of every other digit. For example, if the credit card number is 43589795 . Then you form the sum 5+7+8+ 3=23 - Double each of the digits, which were not included in the preceding step. Add all digits of the resulting numbers. For example, with the number given above, doubling the digits, starting with the next-to-last one, yields 1818108. Adding all digits in these values yields 1+8+1+8+1+0+8= 27. - Add the sums of the two preceding steps. If the last digit of the result is 0 , the number is valid. In our case, 23+27=50, so the number is valid. After the user supplies an 8-digit number, your program should implement the above algorithm, then print out whether the number is a valid credit card number or not. If it is not valid, you should print out the value of the check digit that would make the number valid. Sample output 2: Please enter the 8-digit credit card number (enter 1 to quit) : 43589795 4 Number is valid. Please enter the 8-digit credit card number (enter -1 to quit) : 435897944 Number is invalid. Check digit should have been 5 Please enter the 8 -digit credit card number (enter 1 to quit): 43589793+ Number is invalid. Check digit should have been 5 Please enter the 8 -digit credit card number (enter 1 to quit) : 435897914 Number is invalid. Check digit should have been 5 Please enter the 8-digit credit card number (enter 1 to quit) : 43889795 t Number is invalid. Check digit should have been 9 Please enter the 8-digit credit card number (enter 1 to quit) : 4788979943889799dl Number is valid. Please enter the 8-digit credit card number (enter 1 to quit) : 47889794438897944 Number is invalid. Check digit should have been 9 Please enter the 8-digit credit card number (enter 1 to quit) : 33334444 Number is invalid. Check digit should have been 2 Please enter the 8-digit credit card number (enter 1 to quit): 333344424 Number is valid. Please enter the 8-digit credit card number (enter 1 to quit) : 11111111 Number is invalid