Last Stone Weight

import { Heap } from '@algorithm/lib';
 
export function lastStoneWeight(stones: number[]): number {
  const heap = new Heap<number>((a, b) => b - a);
  for (const stone of stones) {
    heap.push(stone);
  }
 
  while (1 < heap.length) {
    const [stone1, stone2] = [heap.pop(), heap.pop()];
    if (stone1 && stone2 && stone1 !== stone2) {
      heap.push(stone1 - stone2);
    }
  }
 
  return heap.pop() ?? 0;
}