It consisted of two technical rounds and one HR round.

In the first round, I was asked a coding problem that was at a LeetCode medium level.

The next round mainly focused on projects and other CS fundamentals.

Sure, here's a grammatically corrected version of your initial text:

"You are given two arrays of the same length. You have to start from any one of the arrays. While traversing the array, your score is increased by arr[i] if you are at index i. At index i, you can proceed to either i+1 in the current array or switch to the other array. Return the maximum score after reaching the end of either array."