From 91803365aceaef3199e367f03b3a2c4e5f8101bc Mon Sep 17 00:00:00 2001
From: Lam Haoyin <root@eatswap.org>
Date: Sun, 13 Mar 2022 14:39:36 +0800
Subject: [PATCH] add: 220312-CN [cpp]

---
 cpp/2203/220312-CN.cpp  | 38 ++++++++++++++++++++++++++++++++++++++
 cpp/2203/CMakeLists.txt |  2 +-
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 cpp/2203/220312-CN.cpp

diff --git a/cpp/2203/220312-CN.cpp b/cpp/2203/220312-CN.cpp
new file mode 100644
index 0000000..68eed91
--- /dev/null
+++ b/cpp/2203/220312-CN.cpp
@@ -0,0 +1,38 @@
+#include <vector>
+#include <functional>
+
+// Definition for a Node.
+class Node {
+public:
+	int val;
+	std::vector<Node*> children;
+
+	Node(int _val, std::vector<Node*> _children) : val(_val), children(std::move(_children)) {}
+};
+
+/**
+ * 589. N-ary Tree Preorder Traversal
+ * Given the root of an n-ary tree, return the preorder traversal of its nodes' values.
+ * Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples)
+ */
+
+/**
+ * 590. N-ary Tree Postorder Traversal
+ * Given the root of an n-ary tree, return the postorder traversal of its nodes' values.
+ * Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples)
+ */
+
+class Solution {
+public:
+	static std::vector<int> postorder(Node* root) {
+		std::vector<int> ret;
+		std::function<void(const Node* const)> traverse = [&](const Node* const ptr) {
+			if (!ptr) return;
+			for (const Node* const i : ptr->children)
+				traverse(i);
+			ret.push_back(ptr->val);
+		};
+		traverse(root);
+		return ret;
+	}
+};
diff --git a/cpp/2203/CMakeLists.txt b/cpp/2203/CMakeLists.txt
index cbdae08..9701b8c 100644
--- a/cpp/2203/CMakeLists.txt
+++ b/cpp/2203/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2203)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2203 220313.cpp)
+ADD_EXECUTABLE(2203 220312-CN.cpp)