Package g1801_1900.s1872_stone_game_viii

Class Solution

java.lang.Object

g1801_1900.s1872_stone_game_viii.Solution

public class Solution
extends Object

1872 - Stone Game VIII\. Hard Alice and Bob take turns playing a game, with **Alice starting first**. There are `n` stones arranged in a row. On each player's turn, while the number of stones is **more than one** , they will do the following: 1. Choose an integer `x > 1`, and **remove** the leftmost `x` stones from the row. 2. Add the **sum** of the **removed** stones' values to the player's score. 3. Place a **new stone** , whose value is equal to that sum, on the left side of the row. The game stops when **only** **one** stone is left in the row. The **score difference** between Alice and Bob is `(Alice's score - Bob's score)`. Alice's goal is to **maximize** the score difference, and Bob's goal is the **minimize** the score difference. Given an integer array `stones` of length `n` where `stones[i]` represents the value of the ith stone **from the left** , return _the **score difference** between Alice and Bob if they both play **optimally**._ **Example 1:** **Input:** stones = [-1,2,-3,4,-5] **Output:** 5 **Explanation:** - Alice removes the first 4 stones, adds (-1) + 2 + (-3) + 4 = 2 to her score, and places a stone of value 2 on the left. stones = [2,-5]. - Bob removes the first 2 stones, adds 2 + (-5) = -3 to his score, and places a stone of value -3 on the left. stones = [-3]. The difference between their scores is 2 - (-3) = 5. **Example 2:** **Input:** stones = [7,-6,5,10,5,-2,-6] **Output:** 13 **Explanation:** - Alice removes all stones, adds 7 + (-6) + 5 + 10 + 5 + (-2) + (-6) = 13 to her score, and places a stone of value 13 on the left. stones = [13]. The difference between their scores is 13 - 0 = 13. **Example 3:** **Input:** stones = [-10,-12] **Output:** -22 **Explanation:** - Alice can only make one move, which is to remove both stones. She adds (-10) + (-12) = -22 to her score and places a stone of value -22 on the left. stones = [-22]. The difference between their scores is (-22) - 0 = -22. **Constraints:** * `n == stones.length` * 2 <= n <= 105 * -104 <= stones[i] <= 104

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	stoneGameVIII(int[] stones)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

stoneGameVIII

public int stoneGameVIII(int[] stones)