Solution: Last Stone Weight

Statement

You are given an array stones where each element represents the weight of a stone. Repeatedly perform the following operation while there are at least two stones remaining:

Select the two stones with the largest weights, say x and y with x <= y. Smash them together:
If x == y, both stones are destroyed.
If x != y, the stone of weight x is destroyed and the stone of weight y becomes a new stone with weight y - x.

Return the weight of the final remaining stone. If no stones remain, return $0$.

Constraints: