From ba51a4947adb197fcc4551e3157c509795fd0a82 Mon Sep 17 00:00:00 2001 From: ZongqinWang <1722249371@qq.com> Date: Thu, 19 May 2022 11:03:09 +0800 Subject: [PATCH 1/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20199.=E4=BA=8C=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84=E5=8F=B3=E8=A7=86=E5=9B=BE=20Scala=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 25 +++++++++++++++++++++++ 1 file changed, 25 insertions(+) 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/) From 9af80d3007aed88bd8d09538ab6710218c3e9dfd Mon Sep 17 00:00:00 2001 From: ZongqinWang <1722249371@qq.com> Date: Thu, 19 May 2022 11:10:07 +0800 Subject: [PATCH 2/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20637.=E4=BA=8C=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84=E5=B1=82=E5=B9=B3=E5=9D=87=E5=80=BC=20Scala?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 24 +++++++++++++++++++++++ 1 file changed, 24 insertions(+) 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 b74f1a0b..a99449fb 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 @@ -1006,6 +1006,30 @@ func averageOfLevels(_ root: TreeNode?) -> [Double] { return result } ``` +Scala: +```scala +// 637.二叉树的层平均值 +object Solution { + import scala.collection.mutable + def averageOfLevels(root: TreeNode): Array[Double] = { + val res = mutable.ArrayBuffer[Double]() + val queue = mutable.Queue[TreeNode]() + queue.enqueue(root) + while (!queue.isEmpty) { + var sum = 0.0 + var len = queue.size + for (i <- 0 until len) { + var curNode = queue.dequeue() + sum += curNode.value // 累加该层的值 + if (curNode.left != null) queue.enqueue(curNode.left) + if (curNode.right != null) queue.enqueue(curNode.right) + } + res.append(sum / len) // 平均值即为sum/len + } + res.toArray // 最后需要转换为Array，return关键字可以省略 + } +} +``` # 429.N叉树的层序遍历 From c922fbc0e3ee16bbd0f3406227ce51a44cfe636d Mon Sep 17 00:00:00 2001 From: ZongqinWang <1722249371@qq.com> Date: Thu, 19 May 2022 12:19:10 +0800 Subject: [PATCH 3/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20429.N=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84=E5=B1=82=E5=BA=8F=E9=81=8D=E5=8E=86=20Scala?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 28 +++++++++++++++++++++++ 1 file changed, 28 insertions(+) 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 a99449fb..6964e1f0 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 @@ -1274,6 +1274,34 @@ func levelOrder(_ root: Node?) -> [[Int]] { } ``` +Scala: +```scala +// 429.N叉树的层序遍历 +object Solution { + import scala.collection.mutable + def levelOrder(root: Node): List[List[Int]] = { + val res = mutable.ListBuffer[List[Int]]() + if (root == null) return res.toList + val queue = mutable.Queue[Node]() + queue.enqueue(root) // 根节点入队 + while (!queue.isEmpty) { + val tmp = mutable.ListBuffer[Int]() // 存储每层节点 + val len = queue.size + for (i <- 0 until len) { + val curNode = queue.dequeue() + tmp.append(curNode.value) // 将该节点的值加入tmp + // 循环遍历该节点的子节点，加入队列 + for (child <- curNode.children) { + queue.enqueue(child) + } + } + res.append(tmp.toList) // 将该层的节点放到结果集 + } + res.toList + } +} +``` + # 515.在每个树行中找最大值 [力扣题目链接](https://leetcode-cn.com/problems/find-largest-value-in-each-tree-row/)