why is My last two test fails

Question

Am working on my code coch challange "credit card validator " my last 2 test result fails .. can't figure it out why..
Anyone please point out why..
[Code objective: check validity
Input : 16digit number
Output : "valid" or "not valid"
Rules to check validity : given in the code as comment ]
https://code.sololearn.com/cc8bf0WJ8o30/?ref=app

Answer 1

GAME PRO ,

the issue is definitely the missing check for the length of the input number. we do not have to care about other kind of characters, since these are not used in the test cases.
all the other calculations in the code are working properly.

but >>> pay attention to how to get this number. `reversed_digit` is an array for 16 int numbers. so if you check this array for length, you may get always 16 as a result, regardless how many digits the input have.

the condition of the while loop at the beginning of the code should be modified like:

while (n > 0){
digit = n % 10;
n = n /10;
reverse_digit [j] = digit;
j++;
arr_len = j;

after the loop is done, `arr_len` shows the correct length that can be used to verify the correct length:

if (sum % 10 == 0 && arr_len == 16) {
…

Answer 2

Sorry .. I corrected it...

Answer 3

Thanks guys ...I got the it right ..

Answer 4

I took a look at my own solution I made long time ago in C, and I can see that you don't have a condition to check that the input is 16 characters long and only contains numbers from 0 to 9, but I also used string as input type.

I think you should rewrite the code and use string as input instead, and then create the necessary conditions.

Answer 5

I recheck and made some modifications. Which is if wr enter 16 digit .. the code will work as usual. And if enter morethan 16 digit then it will eliminate the extra. And do as before..
https://code.sololearn.com/ckmxiqufpx1D/?ref=app

Answer 6

Quantum I checked it . I couldn't find any flow like that.

Answer 7

I don't know what the locked test cases are looking for, but I can enter any number of letters as input in your code and it returns "valid". Maybe at least one of those cases is checking for anything other than integers?

Answer 8

GAME PRO There is a huge flaw in your program, because if I enter a letter like a, it then says valid. I wonder why the test cases accept that. The test cases seem not to check on letters. That's weird.

Answer 9

Try new code to unique

Answer 10

GAME PRO But it still says valid if you enter a letter as input.

Answer 11

That's better now.