1046 Last Stone Weight

USE A MAX HEAP. Since Python doesn’t support max heaps fully (they do have a few private methods for max heaps, they are very unstable and are recommended not to use - it’s not even in their documentation). So I used Java PriorityQueue<Integer>

Add all elements to the queue, and they will be sorted in a ascending manner. Then maxHeap.poll() the first two elements, check the conditions and maxHeap.offer() them to the queue.

Do this until maxHeap.size() > 1

Code:

Java

class Solution {
    public int lastStoneWeight(int[] stones) {
       PriorityQueue<Integer> maxHeap = new PriorityQueue<>((a,b) -> Integer.compare(b,a)); 
 
        for (int stone: stones) {
            maxHeap.offer(stone);
        }
 
        while (maxHeap.size() > 1) {
            int stone_1 = maxHeap.poll();
            int stone_2 = maxHeap.poll();
 
            maxHeap.offer(Math.abs(stone_1 - stone_2));
        } 
 
        return maxHeap.poll();
 
    }
}

— A

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