I am currently recovered my own algorithm knowledge in https://cp-algorithms.com/. When I entered the category "Binary Exponentiation" and scroll down to practice problems, I can solve all of them except this one: 3722 — Jewel-eating Monsters.
After a long time fixing my code, and my output perfectly matched with given test case in https://udebug.com/, I started feeling there is something wrong with that problem. And I was right, the test cases in ICPC Live Archive was wrong, it contradicted the condition: "It can be assumed (for mysterious reasons) that c is always a prime number."
I am now lost my faith in ICPC Live Archive, because I scared that I will lose my time for debugging the code that I wrote correctly. Will problems with wrong test cases will be fixed, or it will stay as it was forever?