I can pretty much select the digits, multiply the digits by 2 & add the particular digits of the multiplied number. But as of now I can only print them not add them. I also have to add this sum to the remaining numbers in the credit card & then check for modulo 10. How should I do this? Should I change my code(it took me a serious effort to get to this point)?
#include <stdio.h> #include <cs50.h> int main(void) { long long n = get_long("n:"); // gets you CC number int count = 0; int z; int k; int a; int b; int c; int d; while(n / 10 >= 1) { z = n % 10; count++; if(count % 2 == 0) // selects the digit in even places { k = 2*z; // multiplies the digit in even places a = k % 10; // gives 1's place of k b = k / 10; // gives 10's place of k c = a + b; // adds the digit printf("%i\n", c); // this just exists to check whether the above process is happening } n = n / 10; } if(n / 10 == 0) // This helps to find the rightmost digit { z = n % 10; count = count + 1; if(count % 2 == 0) { k = 2*z; a = k % 10; b = k / 10; c = a + b; } } } 
