In Facebook Hacker Cup 2022 Round 2, I coded a right O(n) solution (C++) for Problem A, but I downloaded the input test case and ran the code. but it took me around 8 minutes to get the output. As a result, I couldn't submit the output. However, after the contest, I submitted the output and got accepted. Can anyone please tell me how can I compile fast or overcome this problem or any suggestions regarding this?

Note: I use Codeblocks IDE. Sometimes I use VS Code.