feat: add new lc problems

Author: yanglbme

solution/1500-1599/1581.Customer Who Visited but Did Not Make Any Transactions/README_EN.md

@@ -35,7 +35,7 @@ This table contains information about the transactions made during the visit_id.
 
 <p>&nbsp;</p>
 
-<p>Write an SQL query to find the IDs of the users who visited without making any transactions and the number of times they made these types of visits.</p>
+<p>Write a&nbsp;SQL query to find the IDs of the users who visited without making any transactions and the number of times they made these types of visits.</p>
 
 <p>Return the result table sorted in <strong>any order</strong>.</p>
 

solution/1800-1899/1825.Finding MK Average/README.md

@@ -6,25 +6,25 @@
 
 <!-- 这里写题目描述 -->
 
-<p>给你两个整数 <code>m</code> 和 <code>k</code> ，以及数据流形式的若干整数。你需要实现一个数据结构，计算这个数据流的 <b>MK 平均值</b> 。</p>
+<p>给你两个整数&nbsp;<code>m</code>&nbsp;和&nbsp;<code>k</code>&nbsp;，以及数据流形式的若干整数。你需要实现一个数据结构，计算这个数据流的 <b>MK 平均值</b>&nbsp;。</p>
 
-<p><strong>MK 平均值</strong> 按照如下步骤计算：</p>
+<p><strong>MK 平均值</strong>&nbsp;按照如下步骤计算：</p>
 
 <ol>
-	<li>如果数据流中的整数少于 <code>m</code> 个，<strong>MK 平均值</strong> 为 <code>-1</code> ，否则将数据流中最后 <code>m</code> 个元素拷贝到一个独立的容器中。</li>
-	<li>从这个容器中删除最小的 <code>k</code> 个数和最大的 <code>k</code> 个数。</li>
-	<li>计算剩余元素的平均值，并 <strong>向下取整到最近的整数</strong> 。</li>
+	<li>如果数据流中的整数少于 <code>m</code>&nbsp;个，<strong>MK 平均值</strong>&nbsp;为 <code>-1</code>&nbsp;，否则将数据流中最后 <code>m</code>&nbsp;个元素拷贝到一个独立的容器中。</li>
+	<li>从这个容器中删除最小的 <code>k</code>&nbsp;个数和最大的 <code>k</code>&nbsp;个数。</li>
+	<li>计算剩余元素的平均值，并 <strong>向下取整到最近的整数</strong>&nbsp;。</li>
 </ol>
 
-<p>请你实现 <code>MKAverage</code> 类：</p>
+<p>请你实现&nbsp;<code>MKAverage</code>&nbsp;类：</p>
 
 <ul>
-	<li><code>MKAverage(int m, int k)</code> 用一个空的数据流和两个整数 <code>m</code> 和 <code>k</code> 初始化 <strong>MKAverage</strong> 对象。</li>
-	<li><code>void addElement(int num)</code> 往数据流中插入一个新的元素 <code>num</code> 。</li>
-	<li><code>int calculateMKAverage()</code> 对当前的数据流计算并返回 <strong>MK 平均数</strong> ，结果需 <strong>向下取整到最近的整数</strong> 。</li>
+	<li><code>MKAverage(int m, int k)</code>&nbsp;用一个空的数据流和两个整数 <code>m</code>&nbsp;和 <code>k</code>&nbsp;初始化&nbsp;<strong>MKAverage</strong>&nbsp;对象。</li>
+	<li><code>void addElement(int num)</code>&nbsp;往数据流中插入一个新的元素&nbsp;<code>num</code>&nbsp;。</li>
+	<li><code>int calculateMKAverage()</code>&nbsp;对当前的数据流计算并返回 <strong>MK 平均数</strong>&nbsp;，结果需 <strong>向下取整到最近的整数</strong> 。</li>
 </ul>
 
-<p> </p>
+<p>&nbsp;</p>
 
 <p><strong>示例 1：</strong></p>
 
@@ -42,25 +42,25 @@ obj.addElement(1);        // 当前元素为 [3,1]
 obj.calculateMKAverage(); // 返回 -1 ，因为 m = 3 ，但数据流中只有 2 个元素
 obj.addElement(10);       // 当前元素为 [3,1,10]
 obj.calculateMKAverage(); // 最后 3 个元素为 [3,1,10]
-                          // 删除最小以及最大的 1 个元素后，容器为 <code>[3]
+                          // 删除最小以及最大的 1 个元素后，容器为 [3]
                           // [3] 的平均值等于 3/1 = 3 ，故返回 3
 obj.addElement(5);        // 当前元素为 [3,1,10,5]
 obj.addElement(5);        // 当前元素为 [3,1,10,5,5]
 obj.addElement(5);        // 当前元素为 [3,1,10,5,5,5]
 obj.calculateMKAverage(); // 最后 3 个元素为 [5,5,5]
-                          // </code>删除最小以及最大的 1 个元素后，容器为 <code>[5]<code>
-                          // </code>[5] 的平均值等于 5/1 = 5 ，故返回 5<code>
-</code></code></pre>
+                          // 删除最小以及最大的 1 个元素后，容器为 [5]
+                          // [5] 的平均值等于 5/1 = 5 ，故返回 5
+</pre>
 
-<p> </p>
+<p>&nbsp;</p>
 
 <p><strong>提示：</strong></p>
 
 <ul>
-	<li><code>3 <= m <= 10<sup>5</sup></code></li>
-	<li><code>1 <= k*2 < m</code></li>
-	<li><code>1 <= num <= 10<sup>5</sup></code></li>
-	<li><code>addElement</code> 与 <code>calculateMKAverage</code> 总操作次数不超过 <code>10<sup>5</sup></code> 次。</li>
+	<li><code>3 &lt;= m &lt;= 10<sup>5</sup></code></li>
+	<li><code>1 &lt;= k*2 &lt; m</code></li>
+	<li><code>1 &lt;= num &lt;= 10<sup>5</sup></code></li>
+	<li><code>addElement</code> 与&nbsp;<code>calculateMKAverage</code>&nbsp;总操作次数不超过 <code>10<sup>5</sup></code> 次。</li>
 </ul>
 
 ## 解法

solution/1800-1899/1825.Finding MK Average/README_EN.md

@@ -33,21 +33,21 @@
 [null, null, null, -1, null, 3, null, null, null, 5]
 
 <strong>Explanation</strong>
-MKAverage obj = new MKAverage(3, 1); 
+<code>MKAverage obj = new MKAverage(3, 1); 
 obj.addElement(3);        // current elements are [3]
 obj.addElement(1);        // current elements are [3,1]
 obj.calculateMKAverage(); // return -1, because m = 3 and only 2 elements exist.
 obj.addElement(10);       // current elements are [3,1,10]
 obj.calculateMKAverage(); // The last 3 elements are [3,1,10].
-                          // After removing smallest and largest 1 element the container will be <code>[3].
+                          // After removing smallest and largest 1 element the container will be [3].
                           // The average of [3] equals 3/1 = 3, return 3
 obj.addElement(5);        // current elements are [3,1,10,5]
 obj.addElement(5);        // current elements are [3,1,10,5,5]
 obj.addElement(5);        // current elements are [3,1,10,5,5,5]
 obj.calculateMKAverage(); // The last 3 elements are [5,5,5].
-                          // After removing smallest and largest 1 element the container will be <code>[5].
+                          // After removing smallest and largest 1 element the container will be [5].
                           // The average of [5] equals 5/1 = 5, return 5
-</code></code></pre>
+</code></pre>
 
 <p>&nbsp;</p>
 <p><strong>Constraints:</strong></p>

solution/1800-1899/1828.Queries on Number of Points Inside a Circle/README_EN.md

@@ -104,7 +104,7 @@ public:
             for (auto& p : points) {
                 int i = p[0], j = p[1];
                 int dx = i - x, dy = j - y;
-                cnt += dx * dx + dy * dy <= r * r;   
+                cnt += dx * dx + dy * dy <= r * r;
             }
             ans.emplace_back(cnt);
         }

solution/2500-2599/2539.Count the Number of Good Subsequences/README.md

@@ -0,0 +1,87 @@
+# [2539. Count the Number of Good Subsequences](https://leetcode.cn/problems/count-the-number-of-good-subsequences)
+
+[English Version](/solution/2500-2599/2539.Count%20the%20Number%20of%20Good%20Subsequences/README_EN.md)
+
+## 题目描述
+
+<!-- 这里写题目描述 -->
+
+<p>A <strong>subsequence</strong> of a string is&nbsp;good if it is not empty and the frequency of each one of its characters is the same.</p>
+
+<p>Given a string <code>s</code>, return <em>the number of good subsequences of</em> <code>s</code>. Since the answer may be too large, return it modulo <code>10<sup>9</sup> + 7</code>.</p>
+
+<p>A <strong>subsequence</strong> is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;aabb&quot;
+<strong>Output:</strong> 11
+<strong>Explanation:</strong> The total number of subsequences is <code>2<sup>4</sup>. </code>There are five subsequences which are not good: &quot;<strong><u>aab</u></strong>b&quot;, &quot;a<u><strong>abb</strong></u>&quot;, &quot;<strong><u>a</u></strong>a<u><strong>bb</strong></u>&quot;, &quot;<u><strong>aa</strong></u>b<strong><u>b</u></strong>&quot;, and the empty subsequence. Hence, the number of good subsequences is <code>2<sup>4</sup>-5 = 11</code>.</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;leet&quot;
+<strong>Output:</strong> 12
+<strong>Explanation:</strong> There are four subsequences which are not good: &quot;<strong><u>l</u><em>ee</em></strong>t&quot;, &quot;l<u><strong>eet</strong></u>&quot;, &quot;<strong><u>leet</u></strong>&quot;, and the empty subsequence. Hence, the number of good subsequences is <code>2<sup>4</sup>-4 = 12</code>.
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;abcd&quot;
+<strong>Output:</strong> 15
+<strong>Explanation:</strong> All of the non-empty subsequences are good subsequences. Hence, the number of good subsequences is <code>2<sup>4</sup>-1 = 15</code>.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li>
+	<li><code>s</code> consists of only lowercase English letters.</li>
+</ul>
+
+## 解法
+
+<!-- 这里可写通用的实现逻辑 -->
+
+<!-- tabs:start -->
+
+### **Python3**
+
+<!-- 这里可写当前语言的特殊实现逻辑 -->
+
+```python
+
+```
+
+### **Java**
+
+<!-- 这里可写当前语言的特殊实现逻辑 -->
+
+```java
+
+```
+
+### **C++**
+
+```cpp
+
+```
+
+### **Go**
+
+```go
+
+```
+
+### **...**
+
+```
+
+```
+
+<!-- tabs:end -->

solution/2500-2599/2539.Count the Number of Good Subsequences/README_EN.md

@@ -0,0 +1,79 @@
+# [2539. Count the Number of Good Subsequences](https://leetcode.com/problems/count-the-number-of-good-subsequences)
+
+[中文文档](/solution/2500-2599/2539.Count%20the%20Number%20of%20Good%20Subsequences/README.md)
+
+## Description
+
+<p>A <strong>subsequence</strong> of a string is&nbsp;good if it is not empty and the frequency of each one of its characters is the same.</p>
+
+<p>Given a string <code>s</code>, return <em>the number of good subsequences of</em> <code>s</code>. Since the answer may be too large, return it modulo <code>10<sup>9</sup> + 7</code>.</p>
+
+<p>A <strong>subsequence</strong> is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;aabb&quot;
+<strong>Output:</strong> 11
+<strong>Explanation:</strong> The total number of subsequences is <code>2<sup>4</sup>. </code>There are five subsequences which are not good: &quot;<strong><u>aab</u></strong>b&quot;, &quot;a<u><strong>abb</strong></u>&quot;, &quot;<strong><u>a</u></strong>a<u><strong>bb</strong></u>&quot;, &quot;<u><strong>aa</strong></u>b<strong><u>b</u></strong>&quot;, and the empty subsequence. Hence, the number of good subsequences is <code>2<sup>4</sup>-5 = 11</code>.</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;leet&quot;
+<strong>Output:</strong> 12
+<strong>Explanation:</strong> There are four subsequences which are not good: &quot;<strong><u>l</u><em>ee</em></strong>t&quot;, &quot;l<u><strong>eet</strong></u>&quot;, &quot;<strong><u>leet</u></strong>&quot;, and the empty subsequence. Hence, the number of good subsequences is <code>2<sup>4</sup>-4 = 12</code>.
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;abcd&quot;
+<strong>Output:</strong> 15
+<strong>Explanation:</strong> All of the non-empty subsequences are good subsequences. Hence, the number of good subsequences is <code>2<sup>4</sup>-1 = 15</code>.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li>
+	<li><code>s</code> consists of only lowercase English letters.</li>
+</ul>
+
+## Solutions
+
+<!-- tabs:start -->
+
+### **Python3**
+
+```python
+
+```
+
+### **Java**
+
+```java
+
+```
+
+### **C++**
+
+```cpp
+
+```
+
+### **Go**
+
+```go
+
+```
+
+### **...**
+
+```
+
+```
+
+<!-- tabs:end -->

solution/CONTEST_README.md

@@ -11,8 +11,8 @@
 
 | 段位  | 比例   | 段位名   | 国服分数线    | 勋章                                                                    |
 | ----- | ------ | -------- | --------- | --------------------------------------------------------------------------- |
-| LV3 | 5%  | Guardian | &ge;2247.09 | <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/images/Guardian.gif" style="width: 80px;" /></p> |
-| LV2 | 20% | Knight   | &ge;1881.35 | <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/images/Knight.gif" style="width: 80px;" /></p>   |
+| LV3 | 5%  | Guardian | &ge;2249.79 | <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/images/Guardian.gif" style="width: 80px;" /></p> |
+| LV2 | 20% | Knight   | &ge;1882.71 | <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/images/Knight.gif" style="width: 80px;" /></p>   |
 | LV1 | 75% | -        | -         | -                                                                           |
 
 力扣竞赛 **全国排名前 10** 的用户，全站用户名展示为品牌橙色。

solution/CONTEST_README_EN.md

@@ -13,7 +13,7 @@ If you are in the top 25% of the contest rating, you’ll get the “Knight” b
 
 | Level | Proportion | Badge      | Rating |                                                                                                                         |
 | ----- | ---------- | ---------- | -------------- | ----------------------------------------------------------------------------------------------------------------------- |
-| LV3 | 5\%      | Guardian | &ge;2389.82   | <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/images/Guardian.gif" style="width: 80px;" /></p> |
+| LV3 | 5\%      | Guardian | &ge;2228.90   | <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/images/Guardian.gif" style="width: 80px;" /></p> |
 | LV2 | 20\%     | Knight   | &ge;1842.73   | <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/images/Knight.gif" style="width: 80px;" /></p>   |
 | LV1 | 75\%     | -          | -              | -                                                                                                                       |