Leetcode bcz it's dicussion form is very active, you can see ideas used by others after/before solving a problem.

Leetcode because it has a large question pool and most of its content is free.

The comparison is like HackerEarth or Codeforces !!!(respectively)

One year before your placements are about to start, you should leave CP sites and focus on Leetcode , Interview bit, GFG for problem solving and interview practice and previous questions.

Because the problems in CP are quite different from ones asked in interviews like data structure implementation which you won't be focussing on in CP.

After getting placed you can come back to CP if you wish to :P

Trivago

Interviewbit is basically a selection of most frequent interview questions from LeetCode without the really helpful discussion threads.

(LeetCode >>> Interviewbit)

InterviewBit website is bad. Testcases are wrong in many questions. Python doesn't work in a ton of them. It's weird. Just do leetcode already.

But InterviewBit has a great puzzle section, that's definitely something you should look at.