【877.石子游戏【Python】

Author: hzs

动态规划系列/动态规划之博弈问题.md

@@ -215,4 +215,57 @@ int stoneGame(int[] piles) {
 <img src="../pictures/qrcode.jpg" width=200 >
 </p>
 
-======其他语言代码======
+======其他语言代码======
+
+
+
+
+
+python3版本
+
+由[SCUHZS](https://github.com/brucecat)提供
+
+这里采取的是三维的做法
+
+```python
+class Solution:
+    def stoneGame(self, piles: List[int]) -> bool:
+        n = len(piles)
+
+        # 初始化一个n*n的矩阵 dp数组
+        dp = [[None] * n for i in range(0, n)]
+
+        # 在三角区域填充
+        for i in range(n):
+            for j in range(i, n):
+                dp[i][j] = [0, 0]
+
+        # 填入base case
+        for i in range(0, n):
+            dp[i][i][0] = piles[i]
+            dp[i][i][1] = 0
+
+        # 斜着遍历数组
+        for l in range(2, n + 1):
+            for i in range(0, n-l+1):
+                j = l + i - 1
+
+
+                # 先手选择最左边或最右边的分数
+                left = piles[i] + dp[i + 1][j][1]
+                right = piles[j] + dp[i][j - 1][1]
+
+                # 套用状态转移方程
+                if left > right:
+                    dp[i][j][0] = left
+                    dp[i][j][1] = dp[i + 1][j][0]
+                else:
+                    dp[i][j][0] = right
+                    dp[i][j][1] = dp[i][j - 1][0]
+
+        res = dp[0][n - 1]
+
+        return res[0] - res[1] > 0
+
+```
+