I am able to view solutions of some other users. Are they also able to view mine. If yes, then what is stopping them from copying the code?
Why can I view other people's solutions? Can they view mine? What is stopping people copying other's code?
In general, solutions to a problem are only visible to people who have already solved them themselves, and are accessible for educational purposes.
There are a couple of exceptions. Some very basic problems like TEST have all solutions public to help people get started with CodeChef. After a contest is complete, contest solutions are also made public so you can see how other people have solved the problem.