Hey @suryathakur, his can happen as our judge test your code on some hidden test cases when judging. Passing sample test cases is not enough to get Correct answer.
To solve this, you should think of some other input test cases where your code might be failing.
Your code on is giving correct answer because you have passed the given test cases in the problem statement. But on submission it gives wrong answer because your code had not passed all hidden test cases or edge cases that tend to test your code on input that might give wrong answer if your code is loose and doesn’t cover all aspects of the problem.