添加 0654.最大二叉树.md Scala版本

problems/0654.最大二叉树.md

@@ -476,7 +476,33 @@ func traversal(_ nums: inout [Int], _ left: Int, _ right: Int) -> TreeNode? {
 }
 ```
 
+## Scala
 
+```scala
+object Solution {
+  def constructMaximumBinaryTree(nums: Array[Int]): TreeNode = {
+    if (nums.size == 0) return null
+    // 找到数组最大值
+    var maxIndex = 0
+    var maxValue = Int.MinValue
+    for (i <- nums.indices) {
+      if (nums(i) > maxValue) {
+        maxIndex = i
+        maxValue = nums(i)
+      }
+    }
+
+    // 构建一棵树
+    var root = new TreeNode(maxValue, null, null)
+
+    // 递归寻找左右子树
+    root.left = constructMaximumBinaryTree(nums.slice(0, maxIndex))
+    root.right = constructMaximumBinaryTree(nums.slice(maxIndex + 1, nums.length))
+
+    root // 返回root
+  }
+}
+```
 
 -----------------------
 <div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>