maxSum to a large negative value and ans to 1.level to 0.level.
b. Initialize sumAtCurrentLevel to 0.
c. For each node at the current level (using the size of the queue):
i. Dequeue the node from the queue.
ii. Add the node's value to sumAtCurrentLevel.
iii. Enqueue the node's children (if any) to the queue.
d. If sumAtCurrentLevel is greater than maxSum, update maxSum and ans with the current level.ans.