Package g0801_0900.s0877_stone_game

Class Solution

java.lang.Object
g0801_0900.s0877_stone_game.Solution
public class Solution extends Object
877 - Stone Game.<p>Medium</p> <p>Alice and Bob play a game with piles of stones. There are an <strong>even</strong> number of piles arranged in a row, and each pile has a <strong>positive</strong> integer number of stones <code>piles[i]</code>.</p> <p>The objective of the game is to end with the most stones. The <strong>total</strong> number of stones across all the piles is <strong>odd</strong> , so there are no ties.</p> <p>Alice and Bob take turns, with <strong>Alice starting first</strong>. Each turn, a player takes the entire pile of stones either from the <strong>beginning</strong> or from the <strong>end</strong> of the row. This continues until there are no more piles left, at which point the person with the <strong>most stones wins</strong>.</p> <p>Assuming Alice and Bob play optimally, return <code>true</code> <em>if Alice wins the game, or</em> <code>false</code> <em>if Bob wins</em>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> piles = [5,3,4,5]</p> <p><strong>Output:</strong> true</p> <p><strong>Explanation:</strong></p> <p>Alice starts first, and can only take the first 5 or the last 5.</p> <p>Say she takes the first 5, so that the row becomes [3, 4, 5].</p> <p>If Bob takes 3, then the board is [4, 5], and Alice takes 5 to win with 10 points.</p> <p>If Bob takes the last 5, then the board is [3, 4], and Alice takes 4 to win with 9 points.</p> <p>This demonstrated that taking the first 5 was a winning move for Alice, so we return true.</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> piles = [3,7,2,3]</p> <p><strong>Output:</strong> true</p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 <= piles.length <= 500</code></li> <li><code>piles.length</code> is <strong>even</strong>.</li> <li><code>1 <= piles[i] <= 500</code></li> <li><code>sum(piles[i])</code> is <strong>odd</strong>.</li> </ul>

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • stoneGame

      public boolean stoneGame(int[] piles)