I have a simple question that I have no idea why I still don't have an answer for. Recently I have been watching some streamed YouTube videos of coding contest (ICPC, CodeJam) to keep myself motivated (in fact those top level coders made me feel retarded but that's another story). I saw them generating and testing large amount of input data for their solutions. For example, in medium-hard level questions, generally speaking, input constraint are ~10^5 (this could be number of elements in new lines or size of array). For a guy who is in loves with Visual Studio Code and has no plans of break up, is there any efficient way to generate and test that amount of data? Also, some platforms (like HackerRank) let you download the input output files or other platforms (like CodeForces) let you hack other solutions. So, I was wondering how I could use those files efficiently and how to automate my testing. One obvious option is to write script that will read a file line by line and convert that file into an array then you can use that array as you function input. Any other ideas?