添加 1049.最后一块石头的重量II.md Scala版本

problems/1049.最后一块石头的重量II.md

@@ -152,7 +152,7 @@ public:
 ## 其他语言版本
 
 
-Java：
+### Java：
 
 一维数组版本
 ```Java
@@ -212,7 +212,7 @@ class Solution {
 
 ```
 
-Python：
+### Python：
 ```python
 class Solution:
     def lastStoneWeightII(self, stones: List[int]) -> int:
@@ -225,7 +225,7 @@ class Solution:
         return sumweight -  2 * dp[target]
 ```
 
-Go：
+### Go：
 ```go
 func lastStoneWeightII(stones []int) int {
 	// 15001 = 30 * 1000 /2 +1
@@ -254,7 +254,7 @@ func max(a, b int) int {
 }
 ```
 
-JavaScript版本
+### JavaScript
 
 ```javascript
 /**
@@ -277,7 +277,7 @@ var lastStoneWeightII = function (stones) {
 };
 ```
 
-TypeScript：
+### TypeScript：
 
 ```typescript
 function lastStoneWeightII(stones: number[]): number {
@@ -296,7 +296,47 @@ function lastStoneWeightII(stones: number[]): number {
 };
 ```
 
+### Scala
 
+滚动数组:
+```scala
+object Solution {
+  def lastStoneWeightII(stones: Array[Int]): Int = {
+    var sum = stones.sum
+    var half = sum / 2
+    var dp = new Array[Int](half + 1)
+
+    // 遍历
+    for (i <- 0 until stones.length; j <- half to stones(i) by -1) {
+      dp(j) = math.max(dp(j), dp(j - stones(i)) + stones(i))
+    }
+
+    sum - 2 * dp(half)
+  }
+}
+```
+
+二维数组:
+```scala
+object Solution {
+  def lastStoneWeightII(stones: Array[Int]): Int = {
+    var sum = stones.sum
+    var half = sum / 2
+    var dp = Array.ofDim[Int](stones.length, half + 1)
+
+    // 初始化
+    for (j <- stones(0) to half) dp(0)(j) = stones(0)
+
+    // 遍历
+    for (i <- 1 until stones.length; j <- 1 to half) {
+      if (j - stones(i) >= 0) dp(i)(j) = stones(i) + dp(i - 1)(j - stones(i))
+      dp(i)(j) = math.max(dp(i)(j), dp(i - 1)(j))
+    }
+    
+    sum - 2 * dp(stones.length - 1)(half)
+  }
+}
+```
 
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