Got some homework here. Unfortunately, I have very little experience and have no idea how to solve these. I am not allowed to use replace function/method, global variables and the only collection I'm allowed to use are strings (so no tuples, arrays, etc.). Homework is 10 questions so I will use multiple posts to show them clearly. Any help or explanation would be very appreciated as while I'm ashamed to ask for help this seems way too hard for someone who just started like me.