feat: add solutions to lc problems: No.1880,1881

Author: yanglbme

Diff for: solution/1800-1899/1874.Minimize Product Sum of Two Arrays/README.md

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+# [1874. ](https://leetcode-cn.com/problems/minimize-product-sum-of-two-arrays)
+
+[English Version](/solution/1800-1899/1874.Minimize%20Product%20Sum%20of%20Two%20Arrays/README_EN.md)
+
+## 题目描述
+
+<!-- 这里写题目描述 -->
+
+None
+
+## 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
+
+```
+
+### **...**
+
+```
+
+```
+
+<!-- tabs:end -->

Diff for: solution/1800-1899/1874.Minimize Product Sum of Two Arrays/README_EN.md

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+# [1874. Minimize Product Sum of Two Arrays](https://leetcode.com/problems/minimize-product-sum-of-two-arrays)
+
+[中文文档](/solution/1800-1899/1874.Minimize%20Product%20Sum%20of%20Two%20Arrays/README.md)
+
+## Description
+
+<p>The <b>product sum </b>of two equal-length arrays <code>a</code> and <code>b</code> is equal to the sum of <code>a[i] * b[i]</code> for all <code>0 &lt;= i &lt; a.length</code> (<strong>0-indexed</strong>).</p>
+
+<ul>
+	<li>For example, if <code>a = [1,2,3,4]</code> and <code>b = [5,2,3,1]</code>, the <strong>product sum</strong> would be <code>1*5 + 2*2 + 3*3 + 4*1 = 22</code>.</li>
+</ul>
+
+<p>Given two arrays <code>nums1</code> and <code>nums2</code> of length <code>n</code>, return <em>the <strong>minimum product sum</strong> if you are allowed to <strong>rearrange</strong> the <strong>order</strong> of the elements in </em><code>nums1</code>.&nbsp;</p>
+
+<p>&nbsp;</p>
+
+<p><strong>Example 1:</strong></p>
+
+<pre>
+
+<strong>Input:</strong> nums1 = [5,3,4,2], nums2 = [4,2,2,5]
+
+<strong>Output:</strong> 40
+
+<strong>Explanation:</strong>&nbsp;We can rearrange nums1 to become [3,5,4,2]. The product sum of [3,5,4,2] and [4,2,2,5] is 3*4 + 5*2 + 4*2 + 2*5 = 40.
+
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+
+<strong>Input:</strong> nums1 = [2,1,4,5,7], nums2 = [3,2,4,8,6]
+
+<strong>Output:</strong> 65
+
+<strong>Explanation: </strong>We can rearrange nums1 to become [5,7,4,1,2]. The product sum of [5,7,4,1,2] and [3,2,4,8,6] is 5*3 + 7*2 + 4*4 + 1*8 + 2*6 = 65.
+
+</pre>
+
+<p>&nbsp;</p>
+
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>n == nums1.length == nums2.length</code></li>
+	<li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li>
+	<li><code>1 &lt;= nums1[i], nums2[i] &lt;= 100</code></li>
+</ul>
+
+## Solutions
+
+<!-- tabs:start -->
+
+### **Python3**
+
+```python
+
+```
+
+### **Java**
+
+```java
+
+```
+
+### **...**
+
+```
+
+```
+
+<!-- tabs:end -->

Diff for: solution/1800-1899/1875.Group Employees of the Same Salary/README.md

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+# [1875. ](https://leetcode-cn.com/problems/group-employees-of-the-same-salary)
+
+[English Version](/solution/1800-1899/1875.Group%20Employees%20of%20the%20Same%20Salary/README_EN.md)
+
+## 题目描述
+
+<!-- 这里写题目描述 -->
+
+None
+
+## 解法
+
+<!-- 这里可写通用的实现逻辑 -->
+
+<!-- tabs:start -->
+
+### **SQL**
+
+```sql
+
+```
+
+<!-- tabs:end -->

Diff for: solution/1800-1899/1875.Group Employees of the Same Salary/README_EN.md

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+# [1875. Group Employees of the Same Salary](https://leetcode.com/problems/group-employees-of-the-same-salary)
+
+[中文文档](/solution/1800-1899/1875.Group%20Employees%20of%20the%20Same%20Salary/README.md)
+
+## Description
+
+<p>Table: <code>Employees</code></p>
+
+
+
+<pre>
+
++-------------+---------+
+
+| Column Name | Type    |
+
++-------------+---------+
+
+| employee_id | int     |
+
+| name        | varchar |
+
+| salary      | int     |
+
++-------------+---------+
+
+employee_id is the primary key for this table.
+
+Each row of this table indicates the employee ID, employee name, and salary.
+
+</pre>
+
+
+
+<p>&nbsp;</p>
+
+
+
+<p>A company wants to divide the employees into teams such that all the members on each team have the <strong>same salary</strong>. The teams should follow these criteria:</p>
+
+
+
+<ul>
+	<li>Each team should consist of <strong>at least two</strong> employees.</li>
+	<li>All the employees on a team should have the <strong>same salary</strong>.</li>
+	<li>All the employees of the same salary should be assigned to the same team.</li>
+	<li>If the salary of an employee is unique, we <strong>do not</strong> assign this employee to any team.</li>
+	<li>A team&#39;s ID is assigned based on the <strong>rank of the team&#39;s salary</strong> relative to the other teams&#39; salaries, where the team with the <strong>lowest</strong> salary has <code>team_id = 1</code>. Note that the salaries for employees not on a team are <strong>not included</strong> in this ranking.</li>
+</ul>
+
+
+
+<p>Write an SQL query to get the <code>team_id</code> of each employee that is in a team.</p>
+
+
+
+<p>Return the result table ordered by <code>team_id</code> <strong>in ascending order</strong>. In case of a tie, order it by&nbsp;<code>employee_id</code> in <strong>ascending order</strong>.</p>
+
+
+
+<p>The query result format is in the following example:</p>
+
+
+
+<p>&nbsp;</p>
+
+
+
+<pre>
+
+Employees table:
+
++-------------+---------+--------+
+
+| employee_id | name    | salary |
+
++-------------+---------+--------+
+
+| 2           | Meir    | 3000   |
+
+| 3           | Michael | 3000   |
+
+| 7           | Addilyn | 7400   |
+
+| 8           | Juan    | 6100   |
+
+| 9           | Kannon  | 7400   |
+
++-------------+---------+--------+
+
+
+
+Result table:
+
++-------------+---------+--------+---------+
+
+| employee_id | name    | salary | team_id |
+
++-------------+---------+--------+---------+
+
+| 2           | Meir    | 3000   | 1       |
+
+| 3           | Michael | 3000   | 1       |
+
+| 7           | Addilyn | 7400   | 2       |
+
+| 9           | Kannon  | 7400   | 2       |
+
++-------------+---------+--------+---------+
+
+
+
+Meir (employee_id=2) and Michael (employee_id=3) are in the same team because they have the same salary of 3000.
+
+Addilyn (employee_id=7) and Kannon (employee_id=9) are in the same team because they have the same salary of 7400.
+
+Juan (employee_id=8) is not included in any team because their salary of 6100 is unique (i.e. no other employee has the same salary).
+
+The team IDs are assigned as follows (based on salary ranking, lowest first):
+
+- team_id=1: Meir and Michael, salary of 3000
+
+- team_id=2: Addilyn and Kannon, salary of 7400
+
+Juan&#39;s salary of 6100 is not included in the ranking because they are not on a team.</pre>
+
+## Solutions
+
+<!-- tabs:start -->
+
+### **SQL**
+
+```sql
+
+```
+
+<!-- tabs:end -->

Diff for: solution/1800-1899/1876.Substrings of Size Three with Distinct Characters/README.md

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+# [1876. 长度为三且各字符不同的子字符串](https://leetcode-cn.com/problems/substrings-of-size-three-with-distinct-characters)
+
+[English Version](/solution/1800-1899/1876.Substrings%20of%20Size%20Three%20with%20Distinct%20Characters/README_EN.md)
+
+## 题目描述
+
+<!-- 这里写题目描述 -->
+
+<p>如果一个字符串不含有任何重复字符，我们称这个字符串为 <strong>好</strong> 字符串。</p>
+
+<p>给你一个字符串 <code>s</code> ，请你返回 <code>s</code> 中长度为 <strong>3</strong> 的 <strong>好子字符串</strong> 的数量。</p>
+
+<p>注意，如果相同的好子字符串出现多次，每一次都应该被记入答案之中。</p>
+
+<p><strong>子字符串</strong> 是一个字符串中连续的字符序列。</p>
+
+<p> </p>
+
+<p><strong>示例 1：</strong></p>
+
+<pre>
+<b>输入：</b>s = "xyzzaz"
+<b>输出：</b>1
+<b>解释：</b>总共有 4 个长度为 3 的子字符串："xyz"，"yzz"，"zza" 和 "zaz" 。
+唯一的长度为 3 的好子字符串是 "xyz" 。
+</pre>
+
+<p><strong>示例 2：</strong></p>
+
+<pre>
+<b>输入：</b>s = "aababcabc"
+<b>输出：</b>4
+<b>解释：</b>总共有 7 个长度为 3 的子字符串："aab"，"aba"，"bab"，"abc"，"bca"，"cab" 和 "abc" 。
+好子字符串包括 "abc"，"bca"，"cab" 和 "abc" 。
+</pre>
+
+<p> </p>
+
+<p><strong>提示：</strong></p>
+
+<ul>
+	<li><code>1 <= s.length <= 100</code></li>
+	<li><code>s</code>​​​​​​ 只包含小写英文字母。</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
+
+```
+
+### **...**
+
+```
+
+```
+
+<!-- tabs:end -->