添加 111.二叉树的最小深度 Scala版本

problems/0102.二叉树的层序遍历.md

@@ -2403,6 +2403,30 @@ func minDepth(_ root: TreeNode?) -> Int {
 }
 ```
 
+Scala:
+```scala
+// 111.二叉树的最小深度
+object Solution {
+  import scala.collection.mutable
+  def minDepth(root: TreeNode): Int = {
+    if (root == null) return 0
+    var depth = 0
+    val queue = mutable.Queue[TreeNode]()
+    queue.enqueue(root)
+    while (!queue.isEmpty) {
+      depth += 1
+      val len = queue.size
+      for (i <- 0 until len) {
+        val curNode = queue.dequeue()
+        if (curNode.left != null) queue.enqueue(curNode.left)
+        if (curNode.right != null) queue.enqueue(curNode.right)
+        if (curNode.left == null && curNode.right == null) return depth
+      }
+    }
+    depth
+  }
+}
+```
 
 # 总结