From 601c8144e2d5fd396c0fe0f6aa57eac67e9420e6 Mon Sep 17 00:00:00 2001
From: Matej Focko <me@mfocko.xyz>
Date: Mon, 26 Aug 2024 11:31:42 +0200
Subject: [PATCH] =?UTF-8?q?java:=20add=20=C2=AB590.=20N-ary=20Tree=20Posto?=
 =?UTF-8?q?rder=20Traversal=C2=BB?=
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Signed-off-by: Matej Focko <me@mfocko.xyz>
---
 java/Node.java                           | 18 ++++++++++++++++++
 java/n-ary-tree-postorder-traversal.java | 21 +++++++++++++++++++++
 2 files changed, 39 insertions(+)
 create mode 100644 java/Node.java
 create mode 100644 java/n-ary-tree-postorder-traversal.java

diff --git a/java/Node.java b/java/Node.java
new file mode 100644
index 0000000..87e5f71
--- /dev/null
+++ b/java/Node.java
@@ -0,0 +1,18 @@
+import java.util.List;
+
+public class Node {
+  public int val;
+  public List<Node> children;
+
+  public Node() {}
+
+  public Node(int _val) {
+    val = _val;
+  }
+
+  public Node(int _val, List<Node> _children) {
+    val = _val;
+    children = _children;
+  }
+}
+;
diff --git a/java/n-ary-tree-postorder-traversal.java b/java/n-ary-tree-postorder-traversal.java
new file mode 100644
index 0000000..a763eb7
--- /dev/null
+++ b/java/n-ary-tree-postorder-traversal.java
@@ -0,0 +1,21 @@
+import java.util.ArrayList;
+import java.util.List;
+
+class Solution {
+  private ArrayList<Integer> postorder(Node node, ArrayList<Integer> l) {
+    if (node == null) {
+      return l;
+    }
+
+    for (var child : node.children) {
+      postorder(child, l);
+    }
+    l.add(node.val);
+
+    return l;
+  }
+
+  public List<Integer> postorder(Node root) {
+    return postorder(root, new ArrayList<Integer>());
+  }
+}