2-3 small cases, edge cases, and 1 to test for TLE.

yolo

If I think the logic is correct, I submit my solution. And then I get WA on pretest 2

Depends on the problem and how confident I am on my solution. Usually you can also do a bit of thinking about whether your solution seems intended. For example Div 2A solutions are usually very short and require some quick observation or math formula.

For harder problems if I'm even just somewhat confident I'll just submit. I tend to use Proof By AC, and it usually works. After getting any WA I debug until I find at least one case which was broken, and then fix that and resubmit.

after my code passes the sample cases i go to the next one

I get the intuition before submitting, basically if my code is too complex then i don't submit it ( i think why would setter think of such a shitty solution ) and try to reduce it to a simple solution.

Think some seconds about what would I do if I get WA. Then do just this for like one or two minutes. If I do not spot a bug in that time, then submit.

The "one or two minutes" is less for simple problems, more for later ones.

I read the next problem

It depends on both the problem and the solution. If the problem was very Mathsy and the solution is a few lines I will think about edge cases first and then submit. If the problem required a lot of implementation and my solution looks too ugly I'll just submit and hope for TLE instead of WA.

Get WA on pretest 2.

I generally submit it once if logic seems fine to me. Even if my logic has no proof, it's intuitive, then I try my luck and submit it for once. If its accepted then fine, and if not, then I again try to figure out the correct logic and look for some edge values.

Usually I look at my friends rank list if people who are better than me are getting wrong answer then I look at corner cases,otherwise submit it.

If the sample cases were enough for me to solve the problem on paper, I submit immediately, else I test the code also on the cases that I'd generated on paper.

I do not test my code, I prove it correct.

I try to prove/disprove before coding, think of small edge cases while/after coding and don't submit unless I think that it should pass (sometimes I am wrong). So in case of pretests pass, I move on to next problem.

I look over the standings and check whether I am leading or not