Add: new

README.md

@@ -62,11 +62,20 @@ LeetCode Problems' Solutions
 
 | # | Title | Solution | Difficulty |
 | :-: | - | - | :-: |
+| <span id="1349">1349</span> | [Maximum Students Taking Exam](https://leetcode.com/problems/maximum-students-taking-exam "参加考试的最大学生数") | [Go](problems/maximum-students-taking-exam) | Hard |
+| <span id="1348">1348</span> | [Tweet Counts Per Frequency](https://leetcode.com/problems/tweet-counts-per-frequency "推文计数") | [Go](problems/tweet-counts-per-frequency) | Medium |
+| <span id="1347">1347</span> | [Minimum Number of Steps to Make Two Strings Anagram](https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram "制造字母异位词的最小步骤数") | [Go](problems/minimum-number-of-steps-to-make-two-strings-anagram) | Medium |
+| <span id="1346">1346</span> | [Check If N and Its Double Exist](https://leetcode.com/problems/check-if-n-and-its-double-exist "检查整数及其两倍数是否存在") | [Go](problems/check-if-n-and-its-double-exist) | Easy |
+| <span id="1345">1345</span> | [Jump Game IV](https://leetcode.com/problems/jump-game-iv "跳跃游戏 IV") | [Go](problems/jump-game-iv) | Hard |
+| <span id="1344">1344</span> | [Angle Between Hands of a Clock](https://leetcode.com/problems/angle-between-hands-of-a-clock "时钟指针的夹角") | [Go](problems/angle-between-hands-of-a-clock) | Medium |
+| <span id="1343">1343</span> | [Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold](https://leetcode.com/problems/number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold "大小为 K 且平均值大于等于阈值的子数组数目") | [Go](problems/number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold) | Medium |
+| <span id="1342">1342</span> | [Number of Steps to Reduce a Number to Zero](https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero "将数字变成 0 的操作次数") | [Go](problems/number-of-steps-to-reduce-a-number-to-zero) | Easy |
+| <span id="1341">1341</span> | [Movie Rating](https://leetcode.com/problems/movie-rating "电影评分") 🔒 | [MySQL](problems/movie-rating) | Medium |
 | <span id="1340">1340</span> | [Jump Game V](https://leetcode.com/problems/jump-game-v "跳跃游戏 V") | [Go](problems/jump-game-v) | Hard |
 | <span id="1339">1339</span> | [Maximum Product of Splitted Binary Tree](https://leetcode.com/problems/maximum-product-of-splitted-binary-tree "分裂二叉树的最大乘积") | [Go](problems/maximum-product-of-splitted-binary-tree) | Medium |
 | <span id="1338">1338</span> | [Reduce Array Size to The Half](https://leetcode.com/problems/reduce-array-size-to-the-half "数组大小减半") | [Go](problems/reduce-array-size-to-the-half) | Medium |
 | <span id="1337">1337</span> | [The K Weakest Rows in a Matrix](https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix "方阵中战斗力最弱的 K 行") | [Go](problems/the-k-weakest-rows-in-a-matrix) | Easy |
-| <span id="1336">1336</span> | [Number of Transactions per Visit](https://leetcode.com/problems/number-of-transactions-per-visit) 🔒 | [MySQL](problems/number-of-transactions-per-visit) | Medium |
+| <span id="1336">1336</span> | [Number of Transactions per Visit](https://leetcode.com/problems/number-of-transactions-per-visit) 🔒 | [MySQL](problems/number-of-transactions-per-visit) | Hard |
 | <span id="1335">1335</span> | [Minimum Difficulty of a Job Schedule](https://leetcode.com/problems/minimum-difficulty-of-a-job-schedule "工作计划的最低难度") | [Go](problems/minimum-difficulty-of-a-job-schedule) | Hard |
 | <span id="1334">1334</span> | [Find the City With the Smallest Number of Neighbors at a Threshold Distance](https://leetcode.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance "阈值距离内邻居最少的城市") | [Go](problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance) | Medium |
 | <span id="1333">1333</span> | [Filter Restaurants by Vegan-Friendly, Price and Distance](https://leetcode.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance "餐厅过滤器") | [Go](problems/filter-restaurants-by-vegan-friendly-price-and-distance) | Medium |
@@ -191,14 +200,14 @@ LeetCode Problems' Solutions
 | <span id="1214">1214</span> | [Two Sum BSTs](https://leetcode.com/problems/two-sum-bsts "查找两棵二叉搜索树之和") 🔒 | [Go](problems/two-sum-bsts) | Medium |
 | <span id="1213">1213</span> | [Intersection of Three Sorted Arrays](https://leetcode.com/problems/intersection-of-three-sorted-arrays "三个有序数组的交集") 🔒 | [Go](problems/intersection-of-three-sorted-arrays) | Easy |
 | <span id="1212">1212</span> | [Team Scores in Football Tournament](https://leetcode.com/problems/team-scores-in-football-tournament "查询球队积分") 🔒 | [MySQL](problems/team-scores-in-football-tournament) | Medium |
-| <span id="1211">1211</span> | [Queries Quality and Percentage](https://leetcode.com/problems/queries-quality-and-percentage) 🔒 | [MySQL](problems/queries-quality-and-percentage) | Easy |
+| <span id="1211">1211</span> | [Queries Quality and Percentage](https://leetcode.com/problems/queries-quality-and-percentage "查询结果的质量和占比") 🔒 | [MySQL](problems/queries-quality-and-percentage) | Easy |
 | <span id="1210">1210</span> | [Minimum Moves to Reach Target with Rotations](https://leetcode.com/problems/minimum-moves-to-reach-target-with-rotations "穿过迷宫的最少移动次数") | [Go](problems/minimum-moves-to-reach-target-with-rotations) | Hard |
 | <span id="1209">1209</span> | [Remove All Adjacent Duplicates in String II](https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii "删除字符串中的所有相邻重复项 II") | [Go](problems/remove-all-adjacent-duplicates-in-string-ii) | Medium |
 | <span id="1208">1208</span> | [Get Equal Substrings Within Budget](https://leetcode.com/problems/get-equal-substrings-within-budget "尽可能使字符串相等") | [Go](problems/get-equal-substrings-within-budget) | Medium |
 | <span id="1207">1207</span> | [Unique Number of Occurrences](https://leetcode.com/problems/unique-number-of-occurrences "独一无二的出现次数") | [Go](problems/unique-number-of-occurrences) | Easy |
 | <span id="1206">1206</span> | [Design Skiplist](https://leetcode.com/problems/design-skiplist "设计跳表") | [Go](problems/design-skiplist) | Hard |
 | <span id="1205">1205</span> | [Monthly Transactions II](https://leetcode.com/problems/monthly-transactions-ii "每月交易II") 🔒 | [MySQL](problems/monthly-transactions-ii) | Medium |
-| <span id="1204">1204</span> | [Last Person to Fit in the Elevator](https://leetcode.com/problems/last-person-to-fit-in-the-elevator) 🔒 | [MySQL](problems/last-person-to-fit-in-the-elevator) | Medium |
+| <span id="1204">1204</span> | [Last Person to Fit in the Elevator](https://leetcode.com/problems/last-person-to-fit-in-the-elevator "最后一个能进入电梯的人") 🔒 | [MySQL](problems/last-person-to-fit-in-the-elevator) | Medium |
 | <span id="1203">1203</span> | [Sort Items by Groups Respecting Dependencies](https://leetcode.com/problems/sort-items-by-groups-respecting-dependencies "项目管理") | [Go](problems/sort-items-by-groups-respecting-dependencies) | Hard |
 | <span id="1202">1202</span> | [Smallest String With Swaps](https://leetcode.com/problems/smallest-string-with-swaps "交换字符串中的元素") | [Go](problems/smallest-string-with-swaps) | Medium |
 | <span id="1201">1201</span> | [Ugly Number III](https://leetcode.com/problems/ugly-number-iii "丑数 III") | [Go](problems/ugly-number-iii) | Medium |

problems/angle-between-hands-of-a-clock/README.md

@@ -0,0 +1,79 @@
+<!--|This file generated by command(leetcode description); DO NOT EDIT.    |-->
+<!--+----------------------------------------------------------------------+-->
+<!--|@author    openset <openset.wang@gmail.com>                           |-->
+<!--|@link      https://github.com/openset                                 |-->
+<!--|@home      https://github.com/openset/leetcode                        |-->
+<!--+----------------------------------------------------------------------+-->
+
+[< Previous](../number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold "Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold")
+
+[Next >](../jump-game-iv "Jump Game IV")
+
+## [1344. Angle Between Hands of a Clock (Medium)](https://leetcode.com/problems/angle-between-hands-of-a-clock "时钟指针的夹角")
+
+<p>Given two numbers, <code>hour</code> and <code>minutes</code>. Return the smaller angle (in sexagesimal units) formed between the <code>hour</code> and the <code>minute</code> hand.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<p><img alt="" src="https://assets.leetcode.com/uploads/2019/12/26/sample_1_1673.png" style="width: 230px; height: 225px;" /></p>
+
+<pre>
+<strong>Input:</strong> hour = 12, minutes = 30
+<strong>Output:</strong> 165
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<p><img alt="" src="https://assets.leetcode.com/uploads/2019/12/26/sample_2_1673.png" style="width: 230px; height: 225px;" /></p>
+
+<pre>
+<strong>Input:</strong> hour = 3, minutes = 30
+<strong>Output:</strong> 75
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<p><strong><img alt="" src="https://assets.leetcode.com/uploads/2019/12/26/sample_3_1673.png" style="width: 230px; height: 225px;" /></strong></p>
+
+<pre>
+<strong>Input:</strong> hour = 3, minutes = 15
+<strong>Output:</strong> 7.5
+</pre>
+
+<p><strong>Example 4:</strong></p>
+
+<pre>
+<strong>Input:</strong> hour = 4, minutes = 50
+<strong>Output:</strong> 155
+</pre>
+
+<p><strong>Example 5:</strong></p>
+
+<pre>
+<strong>Input:</strong> hour = 12, minutes = 0
+<strong>Output:</strong> 0
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= hour &lt;= 12</code></li>
+	<li><code>0 &lt;= minutes &lt;= 59</code></li>
+	<li>Answers within&nbsp;<code>10^-5</code>&nbsp;of the actual value will be accepted as correct.</li>
+</ul>
+
+### Related Topics
+  [[Math](../../tag/math/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+The tricky part is determining how the minute hand affects the position of the hour hand.
+</details>
+
+<details>
+<summary>Hint 2</summary>
+Calculate the angles separately then find the difference.
+</details>

problems/check-if-n-and-its-double-exist/README.md

@@ -0,0 +1,69 @@
+<!--|This file generated by command(leetcode description); DO NOT EDIT.    |-->
+<!--+----------------------------------------------------------------------+-->
+<!--|@author    openset <openset.wang@gmail.com>                           |-->
+<!--|@link      https://github.com/openset                                 |-->
+<!--|@home      https://github.com/openset/leetcode                        |-->
+<!--+----------------------------------------------------------------------+-->
+
+[< Previous](../jump-game-iv "Jump Game IV")
+
+[Next >](../minimum-number-of-steps-to-make-two-strings-anagram "Minimum Number of Steps to Make Two Strings Anagram")
+
+## [1346. Check If N and Its Double Exist (Easy)](https://leetcode.com/problems/check-if-n-and-its-double-exist "检查整数及其两倍数是否存在")
+
+<p>Given an array <code>arr</code> of integers, check if there exists two integers <code>N</code> and <code>M</code> such that <code>N</code> is the double of <code>M</code> ( i.e. <code>N = 2 * M</code>).</p>
+
+<p>More formally check if there exists&nbsp;two indices <code>i</code> and <code>j</code> such that :</p>
+
+<ul>
+	<li><code>i != j</code></li>
+	<li><code>0 &lt;= i, j &lt; arr.length</code></li>
+	<li><code>arr[i] == 2 * arr[j]</code></li>
+</ul>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [10,2,5,3]
+<strong>Output:</strong> true
+<strong>Explanation:</strong> N<code> = 10</code> is the double of M<code> = 5</code>,that is, <code>10 = 2 * 5</code>.
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [7,1,14,11]
+<strong>Output:</strong> true
+<strong>Explanation:</strong> N<code> = 14</code> is the double of M<code> = 7</code>,that is, <code>14 = 2 * 7</code>.
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [3,1,7,11]
+<strong>Output:</strong> false
+<strong>Explanation:</strong> In this case does not exist N and M, such that N = 2 * M.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>2 &lt;= arr.length &lt;= 500</code></li>
+	<li><code>-10^3 &lt;= arr[i] &lt;= 10^3</code></li>
+</ul>
+
+### Related Topics
+  [[Array](../../tag/array/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+Loop from i = 0 to arr.length, maintaining in a hashTable the array elements from [0, i - 1].
+</details>
+
+<details>
+<summary>Hint 2</summary>
+On each step of the loop check if we have seen the element 2 * arr[i] so far or arr[i] / 2 was seen if arr[i] % 2 == 0.
+</details>

problems/counting-bits/README.md

@@ -35,8 +35,8 @@
 </ul>
 
 ### Related Topics
-  [[Bit Manipulation](../../tag/bit-manipulation/README.md)]
   [[Dynamic Programming](../../tag/dynamic-programming/README.md)]
+  [[Bit Manipulation](../../tag/bit-manipulation/README.md)]
 
 ### Similar Questions
   1. [Number of 1 Bits](../number-of-1-bits) (Easy)

problems/intersection-of-two-arrays/README.md

@@ -38,10 +38,10 @@
 <p>&nbsp;</p>
 
 ### Related Topics
-  [[Sort](../../tag/sort/README.md)]
   [[Hash Table](../../tag/hash-table/README.md)]
   [[Two Pointers](../../tag/two-pointers/README.md)]
   [[Binary Search](../../tag/binary-search/README.md)]
+  [[Sort](../../tag/sort/README.md)]
 
 ### Similar Questions
   1. [Intersection of Two Arrays II](../intersection-of-two-arrays-ii) (Easy)

problems/jump-game-iv/README.md

@@ -0,0 +1,87 @@
+<!--|This file generated by command(leetcode description); DO NOT EDIT.    |-->
+<!--+----------------------------------------------------------------------+-->
+<!--|@author    openset <openset.wang@gmail.com>                           |-->
+<!--|@link      https://github.com/openset                                 |-->
+<!--|@home      https://github.com/openset/leetcode                        |-->
+<!--+----------------------------------------------------------------------+-->
+
+[< Previous](../angle-between-hands-of-a-clock "Angle Between Hands of a Clock")
+
+[Next >](../check-if-n-and-its-double-exist "Check If N and Its Double Exist")
+
+## [1345. Jump Game IV (Hard)](https://leetcode.com/problems/jump-game-iv "跳跃游戏 IV")
+
+<p>Given an array of&nbsp;integers <code>arr</code>, you are initially positioned at the first index of the array.</p>
+
+<p>In one step you can jump from index <code>i</code> to index:</p>
+
+<ul>
+	<li><code>i + 1</code> where:&nbsp;<code>i + 1 &lt; arr.length</code>.</li>
+	<li><code>i - 1</code> where:&nbsp;<code>i - 1 &gt;= 0</code>.</li>
+	<li><code>j</code> where: <code>arr[i] == arr[j]</code> and <code>i != j</code>.</li>
+</ul>
+
+<p>Return <em>the minimum number of steps</em> to reach the <strong>last index</strong> of the array.</p>
+
+<p>Notice that you can not jump outside of the array at any time.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [100,-23,-23,404,100,23,23,23,3,404]
+<strong>Output:</strong> 3
+<strong>Explanation:</strong> You need three jumps from index 0 --&gt; 4 --&gt; 3 --&gt; 9. Note that index 9 is the last index of the array.
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [7]
+<strong>Output:</strong> 0
+<strong>Explanation:</strong> Start index is the last index. You don&#39;t need to jump.
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [7,6,9,6,9,6,9,7]
+<strong>Output:</strong> 1
+<strong>Explanation:</strong> You can jump directly from index 0 to index 7 which is last index of the array.
+</pre>
+
+<p><strong>Example 4:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [6,1,9]
+<strong>Output:</strong> 2
+</pre>
+
+<p><strong>Example 5:</strong></p>
+
+<pre>
+<strong>Input:</strong> arr = [11,22,7,7,7,7,7,7,7,22,13]
+<strong>Output:</strong> 3
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= arr.length &lt;= 5 * 10^4</code></li>
+	<li><code>-10^8 &lt;= arr[i] &lt;= 10^8</code></li>
+</ul>
+
+### Related Topics
+  [[Breadth-first Search](../../tag/breadth-first-search/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+Build a graph of n nodes where nodes are the indices of the array and edges for node i are nodes i+1, i-1, j where arr[i] == arr[j].
+</details>
+
+<details>
+<summary>Hint 2</summary>
+Start bfs from node 0 and keep distance, answer is the distance when you reach onode n-1.
+</details>

problems/jump-game-v/README.md

@@ -7,7 +7,7 @@
 
 [< Previous](../maximum-product-of-splitted-binary-tree "Maximum Product of Splitted Binary Tree")
 
-Next >
+[Next >](../movie-rating "Movie Rating")
 
 ## [1340. Jump Game V (Hard)](https://leetcode.com/problems/jump-game-v "跳跃游戏 V")
 

problems/last-person-to-fit-in-the-elevator/README.md

@@ -9,7 +9,7 @@
 
 [Next >](../monthly-transactions-ii "Monthly Transactions II")
 
-## [1204. Last Person to Fit in the Elevator (Medium)](https://leetcode.com/problems/last-person-to-fit-in-the-elevator "")
+## [1204. Last Person to Fit in the Elevator (Medium)](https://leetcode.com/problems/last-person-to-fit-in-the-elevator "最后一个能进入电梯的人")
 
 <p>Table: <code>Queue</code></p>