Hello, codeforces. I solved this problem and this cpp code runs very well and gets the correct answers on my local machine.

But when I submit it to codeoforces it gets RTE. I tried to change the compiler but codeforces never run this code. After some debugging, I found that deleting the content of function push solves the RTE but I have no idea why this happens + my entire solution depends on the logic of push. So how do we solve this? Can anyone help me, please?