← All problemsSign in

Card or Discard

Problem description. You are an employee in a cyber-security firm. You have received a mysterious email with an attachment. The attachment is a text file which contains a list of numbers. The email says that some of those sequences are real credit card numbers stolen from customers while shopping online. Write a program to find how many of the sequences are valid credit card numbers in order to

HINT LADDERno hints yet
L1 Observation
L2 Technique
L3 Approach
L4 Pseudo-code
🔒
L5 Full solution
L5 unlocks only if you insist twice
solution.cppC++17

CodeSearch Tutor

Hints, not spoilers — it won’t hand over the full solution unless you insist.

voice by Sarvam AI

Sign in to chat with the tutor and save your progress.

Sign in to start