From a4b2d5557f360d1369dd71081375b0c3c224cd65 Mon Sep 17 00:00:00 2001
From: Lam Haoyin <root@eatswap.org>
Date: Fri, 7 Jan 2022 21:42:21 +0800
Subject: [PATCH] add: 220107

---
 2201/220107-CN.cpp  | 15 +++++++++++++
 2201/220107.cpp     | 54 +++++++++++++++++++++++++++++++++++++++++++++
 2201/CMakeLists.txt |  2 +-
 3 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 2201/220107.cpp

diff --git a/2201/220107-CN.cpp b/2201/220107-CN.cpp
index 776f9a3..3a5369b 100644
--- a/2201/220107-CN.cpp
+++ b/2201/220107-CN.cpp
@@ -1,6 +1,21 @@
 #include <cstdio>
 #include <string>
 
+/**
+ * 1614. Maximum Nesting Depth of the Parentheses
+ * A string is a valid parentheses string (denoted VPS) if it meets one of the following:
+ * It is an empty string "", or a single character not equal to "(" or ")",
+ * It can be written as AB (A concatenated with B), where A and B are VPS's, or
+ * It can be written as (A), where A is a VPS.
+ * We can similarly define the nesting depth depth(S) of any VPS S as follows:
+ * depth("") = 0
+ * depth(C) = 0, where C is a string with a single character not equal to "(" or ")".
+ * depth(A + B) = max(depth(A), depth(B)), where A and B are VPS's.
+ * depth("(" + A + ")") = 1 + depth(A), where A is a VPS.
+ * For example, "", "()()", and "()(()())" are VPS's (with nesting depths 0, 1, and 2), and ")(" and "(()" are not VPS's.
+ * Given a VPS represented as string s, return the nesting depth of s.
+ */
+
 class Solution {
 public:
 	static int maxDepth(const std::string& s) {
diff --git a/2201/220107.cpp b/2201/220107.cpp
new file mode 100644
index 0000000..e722914
--- /dev/null
+++ b/2201/220107.cpp
@@ -0,0 +1,54 @@
+#include <random>
+#include <iostream>
+#include <ctime>
+
+/**
+ * 382. Linked List Random Node
+ * Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen.
+ * Implement the Solution class:
+ * Solution(ListNode head) Initializes the object with the integer array nums.
+ * int getRandom() Chooses a node randomly from the list and returns its value. All the nodes of the list should be equally likely to be choosen.
+ */
+
+/**
+ * Definition for singly-linked list.
+ */
+struct ListNode {
+    int val;
+    ListNode *next;
+    ListNode() : val(0), next(nullptr) {}
+    explicit ListNode(int x) : val(x), next(nullptr) {}
+    ListNode(int x, ListNode *next) : val(x), next(next) {}
+	~ListNode() { delete this->next; }
+};
+
+class Solution {
+private:
+	inline static std::mt19937 r = std::mt19937(std::time(nullptr));
+	int nums[10005]{};
+	int n = 0;
+public:
+	explicit Solution(ListNode* head) {
+		do {
+			nums[n++] = head->val;
+		} while (head = head->next);
+	}
+
+	int getRandom() {
+		return nums[r() % n];
+	}
+};
+
+/**
+ * Your Solution object will be instantiated and called as such:
+ * Solution* obj = new Solution(head);
+ * int param_1 = obj->getRandom();
+ */
+int main() {
+	auto* head = new ListNode(1, new ListNode(2, new ListNode(3)));
+	auto* instance = new Solution(head);
+	std::cout << instance->getRandom() << std::endl;
+	std::cout << instance->getRandom() << std::endl;
+	std::cout << instance->getRandom() << std::endl;
+	return 0;
+}
\ No newline at end of file
diff --git a/2201/CMakeLists.txt b/2201/CMakeLists.txt
index 5318f89..9bcff76 100644
--- a/2201/CMakeLists.txt
+++ b/2201/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2201)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2201 220106.cpp)
\ No newline at end of file
+ADD_EXECUTABLE(2201 220107.cpp)
\ No newline at end of file