diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index ab8f2e57..b74f1a0b 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -750,6 +750,31 @@ func rightSideView(_ root: TreeNode?) -> [Int] { } ``` +Scala: +```scala +// 199.二叉树的右视图 +object Solution { + import scala.collection.mutable + def rightSideView(root: TreeNode): List[Int] = { + val res = mutable.ListBuffer[Int]() + if (root == null) return res.toList + val queue = mutable.Queue[TreeNode]() + queue.enqueue(root) + while (!queue.isEmpty) { + val len = queue.size + var curNode: TreeNode = null + for (i <- 0 until len) { + curNode = queue.dequeue() + if (curNode.left != null) queue.enqueue(curNode.left) + if (curNode.right != null) queue.enqueue(curNode.right) + } + res.append(curNode.value) // 把最后一个节点的值加入解集 + } + res.toList // 最后需要把res转换为List,return关键字可以省略 + } +} +``` + # 637.二叉树的层平均值 [力扣题目链接](https://leetcode-cn.com/problems/average-of-levels-in-binary-tree/)