From dcdda63a84bf8c37deed2bc3cd1183bc35923606 Mon Sep 17 00:00:00 2001
From: Lam Haoyin <root@eatswap.org>
Date: Sat, 25 Dec 2021 11:57:32 +0800
Subject: [PATCH] add: 2021-12-22

---
 2112/211222.cpp     | 47 +++++++++++++++++++++++++++++++++++++++++++++
 2112/CMakeLists.txt |  6 ++++++
 CMakeLists.txt      | 10 ++++++----
 3 files changed, 59 insertions(+), 4 deletions(-)
 create mode 100644 2112/211222.cpp
 create mode 100644 2112/CMakeLists.txt

diff --git a/2112/211222.cpp b/2112/211222.cpp
new file mode 100644
index 0000000..9d6ceee
--- /dev/null
+++ b/2112/211222.cpp
@@ -0,0 +1,47 @@
+#include <vector>
+#include <cstdio>
+
+// Definition for singly-linked list.
+struct ListNode {
+	int val;
+	ListNode* next;
+
+	ListNode() : val(0), next(nullptr) {}
+
+	ListNode(int x) : val(x), next(nullptr) {}
+
+	ListNode(int x, ListNode* next) : val(x), next(next) {}
+
+	~ListNode() { delete this->next; }
+};
+
+class Solution {
+public:
+	static void reorderList(ListNode* head) {
+		ListNode* nodes[50005];
+		int n = 0;
+		do {
+			nodes[n++] = head;
+		} while ((head = head->next) != nullptr);
+		for (int i = 0, j = n - 1; i <= j; ++i, --j) {
+			auto* tmp = nodes[i]->next;
+			nodes[i]->next = nodes[j];
+			nodes[j]->next = nodes[i] == nodes[i]->next || tmp == nodes[j] ? nullptr : tmp;
+		}
+	}
+};
+
+int main() {
+	auto* H = new ListNode(1);
+	auto* ptr = H;
+	for (int i = 2; i <= 17; ++i) {
+		ptr->next = new ListNode(i);
+		ptr = ptr->next;
+	}
+	Solution::reorderList(H);
+	ptr = H;
+	do {
+		std::printf("%d ", ptr->val);
+	} while ((ptr = ptr->next) != nullptr);
+	delete H;
+}
\ No newline at end of file
diff --git a/2112/CMakeLists.txt b/2112/CMakeLists.txt
new file mode 100644
index 0000000..fead261
--- /dev/null
+++ b/2112/CMakeLists.txt
@@ -0,0 +1,6 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 3.21)
+PROJECT(2112)
+
+SET(CMAKE_CXX_STANDARD 23)
+
+ADD_EXECUTABLE(2112 211222.cpp)
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4a5bffa..4bced43 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,8 @@
-cmake_minimum_required(VERSION 3.21)
-project(LeetCodeDaily)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.21)
+PROJECT(LeetCodeDaily)
 
-set(CMAKE_CXX_STANDARD 23)
+SET(CMAKE_CXX_STANDARD 23)
 
-add_executable(LeetCodeDaily main.cpp)
+ADD_EXECUTABLE(LeetCodeDaily main.cpp)
+
+ADD_SUBDIRECTORY(2112)