I saw some previous ZCO questions such as Covering (ZCO 2015: India) where we had pairs of numbers(x,y) which had to be sorted according to the first number. The main problem is once that once we sort the array of x, we need to make sure that each x corresponds to its y. I could think of no method of doing this using sort() so instead I tweaked selection sort(here, Solution: 16200041 ), my solution got accepted since N <= 5000. I wanted to ask, if during the ZCO we will be given small N values in such questions or not? Also, is there a way to do this using sort()?

Thanks.