doocs · yanglbme · Jul 9, 2024 · Jul 9, 2024
diff --git a/lcof2/剑指 Offer II 070. 排序数组中只出现一次的数字/README.md b/lcof2/剑指 Offer II 070. 排序数组中只出现一次的数字/README.md
@@ -158,7 +158,7 @@ class Solution {
     func singleNonDuplicate(_ nums: [Int]) -> Int {
         var left = 0
         var right = nums.count - 1
-        
+
         while left < right {
             let mid = (left + right) / 2
             if nums[mid] != nums[mid ^ 1] {
@@ -167,7 +167,7 @@ class Solution {
                 left = mid + 1
             }
         }
-        
+
         return nums[left]
     }
 }

diff --git a/solution/1800-1899/1823.Find the Winner of the Circular Game/Solution.rs b/solution/1800-1899/1823.Find the Winner of the Circular Game/Solution.rs
@@ -3,7 +3,7 @@ impl Solution {
         if n == 1 {
             return 1;
         }
-		let mut ans = (k + Solution::find_the_winner(n - 1, k)) % n;
-		return if ans == 0 { n } else { ans };
+        let mut ans = (k + Solution::find_the_winner(n - 1, k)) % n;
+        return if ans == 0 { n } else { ans };
     }
 }
diff --git a/solution/3200-3299/3214.Year on Year Growth Rate/README.md b/solution/3200-3299/3214.Year on Year Growth Rate/README.md
@@ -0,0 +1,165 @@
+---
+comments: true
+difficulty: 困难
+edit_url: https://github.com/doocs/leetcode/edit/main/solution/3200-3299/3214.Year%20on%20Year%20Growth%20Rate/README.md
+tags:
+    - 数据库
+---
+
+<!-- problem:start -->
+
+# [3214. Year on Year Growth Rate 🔒](https://leetcode.cn/problems/year-on-year-growth-rate)
+
+[English Version](/solution/3200-3299/3214.Year%20on%20Year%20Growth%20Rate/README_EN.md)
+
+## 题目描述
+
+<!-- description:start -->
+
+<p>Table: <code>user_transactions</code></p>
+
+<pre>
++------------------+----------+
+| Column Name      | Type     | 
++------------------+----------+
+| transaction_id   | integer  |
+| product_id       | integer  |
+| spend            | decimal  |
+| transaction_date | datetime |
++------------------+----------+
+The transaction_id column uniquely identifies each row in this table.
+Each row of this table contains the transaction ID, product ID, the spend amount, and the transaction date.
+</pre>
+
+<p>Write a solution to calculate the <strong>year-on-year growth rate</strong> for the total spend <strong>for each product</strong>.</p>
+
+<p>The result table should include the following columns:</p>
+
+<ul>
+	<li><code>year</code>: The year of the transaction.</li>
+	<li><code>product_id</code>: The ID of the product.</li>
+	<li><code>curr_year_spend</code>: The total spend for the current year.</li>
+	<li><code>prev_year_spend</code>: The total spend for the previous year.</li>
+	<li><code>yoy_rate</code>: The year-on-year growth rate percentage, rounded to <code>2</code> decimal places.</li>
+</ul>
+
+<p>Return <em>the result table ordered by</em>&nbsp;<code>product_id</code>,<code>year</code> <em>in <strong>ascending</strong> order</em>.</p>
+
+<p>The result format is in the following example.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example:</strong></p>
+
+<div class="example-block">
+<p><strong>Input:</strong></p>
+
+<p><code>user_transactions</code> table:</p>
+
+<pre class="example-io">
++----------------+------------+---------+---------------------+
+| transaction_id | product_id | spend   | transaction_date    |
++----------------+------------+---------+---------------------+
+| 1341           | 123424     | 1500.60 | 2019-12-31 12:00:00 |
+| 1423           | 123424     | 1000.20 | 2020-12-31 12:00:00 |
+| 1623           | 123424     | 1246.44 | 2021-12-31 12:00:00 |
+| 1322           | 123424     | 2145.32 | 2022-12-31 12:00:00 |
++----------------+------------+---------+---------------------+
+</pre>
+
+<p><strong>Output:</strong></p>
+
+<pre class="example-io">
++------+------------+----------------+----------------+----------+
+| year | product_id | curr_year_spend| prev_year_spend| yoy_rate |
++------+------------+----------------+----------------+----------+
+| 2019 | 123424     | 1500.60        | NULL           | NULL     |
+| 2020 | 123424     | 1000.20        | 1500.60        | -33.35   |
+| 2021 | 123424     | 1246.44        | 1000.20        | 24.62    |
+| 2022 | 123424     | 2145.32        | 1246.44        | 72.12    |
++------+------------+----------------+----------------+----------+
+</pre>
+
+<p><strong>Explanation:</strong></p>
+
+<ul>
+	<li>For product ID 123424:
+	<ul>
+		<li>In 2019:
+		<ul>
+			<li>Current year&#39;s spend is 1500.60</li>
+			<li>No previous year&#39;s spend recorded</li>
+			<li>YoY growth rate: NULL</li>
+		</ul>
+		</li>
+		<li>In 2020:
+		<ul>
+			<li>Current year&#39;s spend is 1000.20</li>
+			<li>Previous year&#39;s spend is 1500.60</li>
+			<li>YoY growth rate: ((1000.20 - 1500.60) / 1500.60) * 100 = -33.35%</li>
+		</ul>
+		</li>
+		<li>In 2021:
+		<ul>
+			<li>Current year&#39;s spend is 1246.44</li>
+			<li>Previous year&#39;s spend is 1000.20</li>
+			<li>YoY growth rate: ((1246.44 - 1000.20) / 1000.20) * 100 = 24.62%</li>
+		</ul>
+		</li>
+		<li>In 2022:
+		<ul>
+			<li>Current year&#39;s spend is 2145.32</li>
+			<li>Previous year&#39;s spend is 1246.44</li>
+			<li>YoY growth rate: ((2145.32 - 1246.44) / 1246.44) * 100 = 72.12%</li>
+		</ul>
+		</li>
+	</ul>
+	</li>
+</ul>
+
+<p><strong>Note:</strong> Output table is ordered by <code>product_id</code> and <code>year</code> in ascending order.</p>
+</div>
+
+<!-- description:end -->
+
+## 解法
+
+<!-- solution:start -->
+
+### 方法一：分组统计 + 窗口函数
+
+我们可以先按照年份和产品 ID 进行分组统计每个产品每年的总花费，记录在 `T` 表中。然后使用窗口函数 `LAG` 计算出上一年的总花费，记录在 `S` 表中。最后根据公式计算出年增长率。
+
+<!-- tabs:start -->
+
+#### MySQL
+
+```sql
+# Write your MySQL query statement below
+WITH
+    T AS (
+        SELECT YEAR(transaction_date) year, product_id, SUM(spend) tot_spend
+        FROM user_transactions
+        GROUP BY 1, 2
+    ),
+    S AS (
+        SELECT
+            year,
+            product_id,
+            tot_spend curr_year_spend,
+            LAG(tot_spend) OVER (
+                PARTITION BY product_id
+                ORDER BY year
+            ) prev_year_spend
+        FROM T
+    )
+SELECT
+    *,
+    ROUND((curr_year_spend - prev_year_spend) / prev_year_spend * 100, 2) yoy_rate
+FROM S;
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
+<!-- problem:end -->
diff --git a/solution/3200-3299/3214.Year on Year Growth Rate/README_EN.md b/solution/3200-3299/3214.Year on Year Growth Rate/README_EN.md
@@ -0,0 +1,165 @@
+---
+comments: true
+difficulty: Hard
+edit_url: https://github.com/doocs/leetcode/edit/main/solution/3200-3299/3214.Year%20on%20Year%20Growth%20Rate/README_EN.md
+tags:
+    - Database
+---
+
+<!-- problem:start -->
+
+# [3214. Year on Year Growth Rate 🔒](https://leetcode.com/problems/year-on-year-growth-rate)
+
+[中文文档](/solution/3200-3299/3214.Year%20on%20Year%20Growth%20Rate/README.md)
+
+## Description
+
+<!-- description:start -->
+
+<p>Table: <code>user_transactions</code></p>
+
+<pre>
++------------------+----------+
+| Column Name      | Type     | 
++------------------+----------+
+| transaction_id   | integer  |
+| product_id       | integer  |
+| spend            | decimal  |
+| transaction_date | datetime |
++------------------+----------+
+The transaction_id column uniquely identifies each row in this table.
+Each row of this table contains the transaction ID, product ID, the spend amount, and the transaction date.
+</pre>
+
+<p>Write a solution to calculate the <strong>year-on-year growth rate</strong> for the total spend <strong>for each product</strong>.</p>
+
+<p>The result table should include the following columns:</p>
+
+<ul>
+	<li><code>year</code>: The year of the transaction.</li>
+	<li><code>product_id</code>: The ID of the product.</li>
+	<li><code>curr_year_spend</code>: The total spend for the current year.</li>
+	<li><code>prev_year_spend</code>: The total spend for the previous year.</li>
+	<li><code>yoy_rate</code>: The year-on-year growth rate percentage, rounded to <code>2</code> decimal places.</li>
+</ul>
+
+<p>Return <em>the result table ordered by</em>&nbsp;<code>product_id</code>,<code>year</code> <em>in <strong>ascending</strong> order</em>.</p>
+
+<p>The result format is in the following example.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example:</strong></p>
+
+<div class="example-block">
+<p><strong>Input:</strong></p>
+
+<p><code>user_transactions</code> table:</p>
+
+<pre class="example-io">
++----------------+------------+---------+---------------------+
+| transaction_id | product_id | spend   | transaction_date    |
++----------------+------------+---------+---------------------+
+| 1341           | 123424     | 1500.60 | 2019-12-31 12:00:00 |
+| 1423           | 123424     | 1000.20 | 2020-12-31 12:00:00 |
+| 1623           | 123424     | 1246.44 | 2021-12-31 12:00:00 |
+| 1322           | 123424     | 2145.32 | 2022-12-31 12:00:00 |
++----------------+------------+---------+---------------------+
+</pre>
+
+<p><strong>Output:</strong></p>
+
+<pre class="example-io">
++------+------------+----------------+----------------+----------+
+| year | product_id | curr_year_spend| prev_year_spend| yoy_rate |
++------+------------+----------------+----------------+----------+
+| 2019 | 123424     | 1500.60        | NULL           | NULL     |
+| 2020 | 123424     | 1000.20        | 1500.60        | -33.35   |
+| 2021 | 123424     | 1246.44        | 1000.20        | 24.62    |
+| 2022 | 123424     | 2145.32        | 1246.44        | 72.12    |
++------+------------+----------------+----------------+----------+
+</pre>
+
+<p><strong>Explanation:</strong></p>
+
+<ul>
+	<li>For product ID 123424:
+	<ul>
+		<li>In 2019:
+		<ul>
+			<li>Current year&#39;s spend is 1500.60</li>
+			<li>No previous year&#39;s spend recorded</li>
+			<li>YoY growth rate: NULL</li>
+		</ul>
+		</li>
+		<li>In 2020:
+		<ul>
+			<li>Current year&#39;s spend is 1000.20</li>
+			<li>Previous year&#39;s spend is 1500.60</li>
+			<li>YoY growth rate: ((1000.20 - 1500.60) / 1500.60) * 100 = -33.35%</li>
+		</ul>
+		</li>
+		<li>In 2021:
+		<ul>
+			<li>Current year&#39;s spend is 1246.44</li>
+			<li>Previous year&#39;s spend is 1000.20</li>
+			<li>YoY growth rate: ((1246.44 - 1000.20) / 1000.20) * 100 = 24.62%</li>
+		</ul>
+		</li>
+		<li>In 2022:
+		<ul>
+			<li>Current year&#39;s spend is 2145.32</li>
+			<li>Previous year&#39;s spend is 1246.44</li>
+			<li>YoY growth rate: ((2145.32 - 1246.44) / 1246.44) * 100 = 72.12%</li>
+		</ul>
+		</li>
+	</ul>
+	</li>
+</ul>
+
+<p><strong>Note:</strong> Output table is ordered by <code>product_id</code> and <code>year</code> in ascending order.</p>
+</div>
+
+<!-- description:end -->
+
+## Solutions
+
+<!-- solution:start -->
+
+### Solution 1: Grouping Statistics + Window Function
+
+We can first group by year and product ID to calculate the total cost of each product every year, recorded in table `T`. Then, use the window function `LAG` to calculate the total cost of the previous year, recorded in table `S`. Finally, calculate the annual growth rate based on the formula.
+
+<!-- tabs:start -->
+
+#### MySQL
+
+```sql
+# Write your MySQL query statement below
+WITH
+    T AS (
+        SELECT YEAR(transaction_date) year, product_id, SUM(spend) tot_spend
+        FROM user_transactions
+        GROUP BY 1, 2
+    ),
+    S AS (
+        SELECT
+            year,
+            product_id,
+            tot_spend curr_year_spend,
+            LAG(tot_spend) OVER (
+                PARTITION BY product_id
+                ORDER BY year
+            ) prev_year_spend
+        FROM T
+    )
+SELECT
+    *,
+    ROUND((curr_year_spend - prev_year_spend) / prev_year_spend * 100, 2) yoy_rate
+FROM S;
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
+<!-- problem:end -->
diff --git a/solution/3200-3299/3214.Year on Year Growth Rate/Solution.sql b/solution/3200-3299/3214.Year on Year Growth Rate/Solution.sql
@@ -0,0 +1,22 @@
+# Write your MySQL query statement below
+WITH
+    T AS (
+        SELECT YEAR(transaction_date) year, product_id, SUM(spend) tot_spend
+        FROM user_transactions
+        GROUP BY 1, 2
+    ),
+    S AS (
+        SELECT
+            year,
+            product_id,
+            tot_spend curr_year_spend,
+            LAG(tot_spend) OVER (
+                PARTITION BY product_id
+                ORDER BY year
+            ) prev_year_spend
+        FROM T
+    )
+SELECT
+    *,
+    ROUND((curr_year_spend - prev_year_spend) / prev_year_spend * 100, 2) yoy_rate
+FROM S;
diff --git a/solution/DATABASE_README.md b/solution/DATABASE_README.md
@@ -286,6 +286,7 @@
 | 3188 | [查找得分最高的学生 II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README.md)                                                             | `数据库` | 困难 | 🔒   |
 | 3198 | [查找每个州的城市](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README.md)                                                                     | `数据库` | 简单 | 🔒   |
 | 3204 | [按位用户权限分析](/solution/3200-3299/3204.Bitwise%20User%20Permissions%20Analysis/README.md)                                                               | `数据库` | 中等 | 🔒   |
+| 3214 | [Year on Year Growth Rate](/solution/3200-3299/3214.Year%20on%20Year%20Growth%20Rate/README.md)                                                              | `数据库` | 困难 | 🔒   |
 
 ## 版权
 

diff --git a/solution/DATABASE_README_EN.md b/solution/DATABASE_README_EN.md
@@ -284,6 +284,7 @@ Press <kbd>Control</kbd> + <kbd>F</kbd>(or <kbd>Command</kbd> + <kbd>F</kbd> on
 | 3188 | [Find Top Scoring Students II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README_EN.md)                                                                                   | `Database` | Hard       | 🔒     |
 | 3198 | [Find Cities in Each State](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README_EN.md)                                                                                         | `Database` | Easy       | 🔒     |
 | 3204 | [Bitwise User Permissions Analysis](/solution/3200-3299/3204.Bitwise%20User%20Permissions%20Analysis/README_EN.md)                                                                           | `Database` | Medium     | 🔒     |
+| 3214 | [Year on Year Growth Rate](/solution/3200-3299/3214.Year%20on%20Year%20Growth%20Rate/README_EN.md)                                                                                           | `Database` | Hard       | 🔒     |
 
 ## Copyright