Hard
Given nums (the value of each stone in a row), Alice and Bob alternate turns with Alice first. On a turn a player takes the first 1, 2, or 3 remaining stones. Both play optimally to maximize their own total. Return Alice's score minus Bob's score (positive if Alice wins, negative if Bob wins, 0 for a tie).
Input: nums = [1,2,3,7] Output: -4
Input: nums = [1,2,3,6] Output: 0