Top K Elements , Java Patterns, Integer Overflow in Max Heap Comparator for K Closest Points to Origin, problem on LeetCode 973.

[Arnab7456]

The original comparator: PriorityQueue<int[]> maxHeap = new PriorityQueue<>((a, b) -> getDistance(b) - getDistance(a)); Here, getDistance(b) - getDistance(a) could result in overflow if the distances are large, causing incorrect behavior or errors. Proposed Solution: To avoid the risk of overflow, it is recommended that the comparator be changed to

Integer.compare():

PriorityQueue<int[]> maxHeap = new PriorityQueue<>((a, b) -> Integer.compare(getDistance(b), getDistance(a)));

This change ensures that the distances are compared safely without the risk of overflow.

Steps to Reproduce: Use the provided solution for the "K Closest Points to Origin" problem on LeetCode 973. Test the solution with a large number of points (e.g., with coordinates in the range of [-10^4, 10^4]). Observe that the original comparator could result in integer overflow due to the subtraction of large numbers.

Expected Behavior: The solution should compare the distances correctly without any risk of overflow. The use of Integer.compare() ensures safe comparisons between distances.

Actual Behavior: The current implementation can potentially cause overflow when the distances are large.