1049 - Last Stone Weight II.

Medium

You are given an array of integers stones where stones[i] is the weight of the <code>i^th</code> stone.

We are playing a game with the stones. On each turn, we choose any two stones and smash them together. Suppose the stones have weights x and y with x <= y. The result of this smash is:

• If x == y, both stones are destroyed, and

• If x != y, the stone of weight x is destroyed, and the stone of weight y has new weight y - x.

At the end of the game, there is at most one stone left.

Return the smallest possible weight of the left stone. If there are no stones left, return 0.

Example 1:

Input: stones = 2,7,4,1,8,1

Output: 1

Explanation:

We can combine 2 and 4 to get 2, so the array converts to 2,7,1,8,1 then,

we can combine 7 and 8 to get 1, so the array converts to 2,1,1,1 then,

we can combine 2 and 1 to get 1, so the array converts to 1,1,1 then,

we can combine 1 and 1 to get 0, so the array converts to 1, then that's the optimal value.

Example 2:

Input: stones = 31,26,33,21,40

Output: 5

Constraints:

• 1 <= stones.length <= 30

• 1 <= stones[i] <= 100