Kattis Challenge: Phone List, 4-Second Time Limit Exceeded, C#
问题 Using the online automated testing system Kattis, I'm challenged (in C#) with the task of creating a list of phone numbers then finding out if any of them is a prefix or another. (see: https://ncpc.idi.ntnu.no/ncpc2007/ncpc2007problems.pdf, task A) Providing the answer was relatively easy, but no matter how I try I cannot escape getting the Result: Time Limit Exceeded, with some further information saying it took over 4 seconds to run the program (by an automated program). I have tried