Merge pull request #781 from openset/develop

A: new

Author: Shuo

README.md

@@ -62,6 +62,11 @@ LeetCode Problems' Solutions
 
 | # | Title | Solution | Difficulty |
 | :-: | - | - | :-: |
+| <span id="1411">1411</span> | [Number of Ways to Paint N × 3 Grid](https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid "给 N x 3 网格图涂色的方案数") | [Go](problems/number-of-ways-to-paint-n-3-grid) | Hard |
+| <span id="1410">1410</span> | [HTML Entity Parser](https://leetcode.com/problems/html-entity-parser "HTML 实体解析器") | [Go](problems/html-entity-parser) | Medium |
+| <span id="1409">1409</span> | [Queries on a Permutation With Key](https://leetcode.com/problems/queries-on-a-permutation-with-key "查询带键的排列") | [Go](problems/queries-on-a-permutation-with-key) | Medium |
+| <span id="1408">1408</span> | [String Matching in an Array](https://leetcode.com/problems/string-matching-in-an-array "数组中的字符串匹配") | [Go](problems/string-matching-in-an-array) | Easy |
+| <span id="1407">1407</span> | [Top Travellers](https://leetcode.com/problems/top-travellers) 🔒 | [MySQL](problems/top-travellers) | Easy |
 | <span id="1406">1406</span> | [Stone Game III](https://leetcode.com/problems/stone-game-iii "石子游戏 III") | [Go](problems/stone-game-iii) | Hard |
 | <span id="1405">1405</span> | [Longest Happy String](https://leetcode.com/problems/longest-happy-string "最长快乐字符串") | [Go](problems/longest-happy-string) | Medium |
 | <span id="1404">1404</span> | [Number of Steps to Reduce a Number in Binary Representation to One](https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one "将二进制表示减到 1 的步骤数") | [Go](problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one) | Medium |
@@ -70,7 +75,7 @@ LeetCode Problems' Solutions
 | <span id="1401">1401</span> | [Circle and Rectangle Overlapping](https://leetcode.com/problems/circle-and-rectangle-overlapping "圆和矩形是否有重叠") | [Go](problems/circle-and-rectangle-overlapping) | Medium |
 | <span id="1400">1400</span> | [Construct K Palindrome Strings](https://leetcode.com/problems/construct-k-palindrome-strings "构造 K 个回文字符串") | [Go](problems/construct-k-palindrome-strings) | Medium |
 | <span id="1399">1399</span> | [Count Largest Group](https://leetcode.com/problems/count-largest-group "统计最大组的数目") | [Go](problems/count-largest-group) | Easy |
-| <span id="1398">1398</span> | [Customers Who Bought Products A and B but Not C](https://leetcode.com/problems/customers-who-bought-products-a-and-b-but-not-c) 🔒 | [MySQL](problems/customers-who-bought-products-a-and-b-but-not-c) | Medium |
+| <span id="1398">1398</span> | [Customers Who Bought Products A and B but Not C](https://leetcode.com/problems/customers-who-bought-products-a-and-b-but-not-c "购买了产品A和产品B却没有购买产品C的顾客") 🔒 | [MySQL](problems/customers-who-bought-products-a-and-b-but-not-c) | Medium |
 | <span id="1397">1397</span> | [Find All Good Strings](https://leetcode.com/problems/find-all-good-strings "找到所有好字符串") | [Go](problems/find-all-good-strings) | Hard |
 | <span id="1396">1396</span> | [Design Underground System](https://leetcode.com/problems/design-underground-system "设计地铁系统") | [Go](problems/design-underground-system) | Medium |
 | <span id="1395">1395</span> | [Count Number of Teams](https://leetcode.com/problems/count-number-of-teams "统计作战单位数") | [Go](problems/count-number-of-teams) | Medium |
@@ -474,7 +479,7 @@ LeetCode Problems' Solutions
 | <span id="997">997</span> | [Find the Town Judge](https://leetcode.com/problems/find-the-town-judge "找到小镇的法官") | [Go](problems/find-the-town-judge) | Easy |
 | <span id="996">996</span> | [Number of Squareful Arrays](https://leetcode.com/problems/number-of-squareful-arrays "正方形数组的数目") | [Go](problems/number-of-squareful-arrays) | Hard |
 | <span id="995">995</span> | [Minimum Number of K Consecutive Bit Flips](https://leetcode.com/problems/minimum-number-of-k-consecutive-bit-flips "K 连续位的最小翻转次数") | [Go](problems/minimum-number-of-k-consecutive-bit-flips) | Hard |
-| <span id="994">994</span> | [Rotting Oranges](https://leetcode.com/problems/rotting-oranges "腐烂的橘子") | [Go](problems/rotting-oranges) | Easy |
+| <span id="994">994</span> | [Rotting Oranges](https://leetcode.com/problems/rotting-oranges "腐烂的橘子") | [Go](problems/rotting-oranges) | Medium |
 | <span id="993">993</span> | [Cousins in Binary Tree](https://leetcode.com/problems/cousins-in-binary-tree "二叉树的堂兄弟节点") | [Go](problems/cousins-in-binary-tree) | Easy |
 | <span id="992">992</span> | [Subarrays with K Different Integers](https://leetcode.com/problems/subarrays-with-k-different-integers "K 个不同整数的子数组") | [Go](problems/subarrays-with-k-different-integers) | Hard |
 | <span id="991">991</span> | [Broken Calculator](https://leetcode.com/problems/broken-calculator "坏了的计算器") | [Go](problems/broken-calculator) | Medium |

problems/best-time-to-buy-and-sell-stock-ii/README.md

@@ -11,7 +11,7 @@
 
 ## [122. Best Time to Buy and Sell Stock II (Easy)](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii "买卖股票的最佳时机 II")
 
-<p>Say you have an array for which the <em>i</em><sup>th</sup> element is the price of a given stock on day <em>i</em>.</p>
+<p>Say you have an array <code>prices</code> for which the <em>i</em><sup>th</sup> element is the price of a given stock on day <em>i</em>.</p>
 
 <p>Design an algorithm to find the maximum profit. You may complete as many transactions as you like (i.e., buy one and sell one share of the stock multiple times).</p>
 
@@ -43,6 +43,14 @@
 <strong>Output:</strong> 0
 <strong>Explanation:</strong> In this case, no transaction is done, i.e. max profit = 0.</pre>
 
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= prices.length &lt;= 3 * 10 ^ 4</code></li>
+	<li><code>0 &lt;= prices[i]&nbsp;&lt;= 10 ^ 4</code></li>
+</ul>
+
 ### Related Topics
   [[Greedy](../../tag/greedy/README.md)]
   [[Array](../../tag/array/README.md)]

problems/customers-who-bought-products-a-and-b-but-not-c/README.md

@@ -9,6 +9,6 @@
 
 [Next >](../count-largest-group "Count Largest Group")
 
-## [1398. Customers Who Bought Products A and B but Not C (Medium)](https://leetcode.com/problems/customers-who-bought-products-a-and-b-but-not-c "")
+## [1398. Customers Who Bought Products A and B but Not C (Medium)](https://leetcode.com/problems/customers-who-bought-products-a-and-b-but-not-c "购买了产品A和产品B却没有购买产品C的顾客")
 
 

problems/fizz-buzz/README.md

@@ -39,3 +39,6 @@ Return:
 ]
 </pre>
 </p>
+
+### Similar Questions
+  1. [Fizz Buzz Multithreaded](../fizz-buzz-multithreaded) (Medium)

problems/happy-number/README.md

@@ -11,9 +11,11 @@
 
 ## [202. Happy Number (Easy)](https://leetcode.com/problems/happy-number "快乐数")
 
-<p>Write an algorithm to determine if a number is &quot;happy&quot;.</p>
+<p>Write an algorithm to determine if a number <code>n</code> is &quot;happy&quot;.</p>
 
-<p>A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.</p>
+<p>A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it <strong>loops endlessly in a cycle</strong> which does not include 1. Those numbers for which this process <strong>ends in 1</strong> are happy numbers.</p>
+
+<p>Return True if <code>n</code> is a happy number, and False if not.</p>
 
 <p><strong>Example:&nbsp;</strong></p>
 

problems/html-entity-parser/README.md

@@ -0,0 +1,89 @@
+<!--|This file generated by command(leetcode description); DO NOT EDIT.    |-->
+<!--+----------------------------------------------------------------------+-->
+<!--|@author    openset <[email protected]>                           |-->
+<!--|@link      https://github.com/openset                                 |-->
+<!--|@home      https://github.com/openset/leetcode                        |-->
+<!--+----------------------------------------------------------------------+-->
+
+[< Previous](../queries-on-a-permutation-with-key "Queries on a Permutation With Key")
+　　　　　　　　　　　　　　　　
+[Next >](../number-of-ways-to-paint-n-3-grid "Number of Ways to Paint N × 3 Grid")
+
+## [1410. HTML Entity Parser (Medium)](https://leetcode.com/problems/html-entity-parser "HTML 实体解析器")
+
+<p><strong>HTML entity parser</strong> is the parser that takes HTML code as input and replace all the entities of the special characters by the characters itself.</p>
+
+<p>The special characters and their entities for HTML are:</p>
+
+<ul>
+	<li><strong>Quotation Mark:</strong>&nbsp;the entity is <code>&amp;quot;</code> and&nbsp;symbol character is <code>&quot;</code>.</li>
+	<li><strong>Single Quote&nbsp;Mark:</strong>&nbsp;the entity is <code>&amp;apos;</code> and&nbsp;symbol character is <code>&#39;</code>.</li>
+	<li><strong>Ampersand:</strong>&nbsp;the entity is <code>&amp;amp;</code> and symbol character is <code>&amp;</code>.</li>
+	<li><strong>Greater Than Sign:</strong>&nbsp;the entity is <code>&amp;gt;</code>&nbsp;and symbol character is <code>&gt;</code>.</li>
+	<li><strong>Less Than Sign:</strong>&nbsp;the entity is <code>&amp;lt;</code>&nbsp;and symbol character is <code>&lt;</code>.</li>
+	<li><strong>Slash:</strong>&nbsp;the entity is <code>&amp;frasl;</code> and&nbsp;symbol character is <code>/</code>.</li>
+</ul>
+
+<p>Given the input <code>text</code> string to the HTML parser, you have to implement the entity parser.</p>
+
+<p>Return <em>the text</em> after replacing the entities by the special characters.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> text = &quot;&amp;amp; is an HTML entity but &amp;ambassador; is not.&quot;
+<strong>Output:</strong> &quot;&amp; is an HTML entity but &amp;ambassador; is not.&quot;
+<strong>Explanation:</strong> The parser will replace the &amp;amp; entity by &amp;
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> text = &quot;and I quote: &amp;quot;...&amp;quot;&quot;
+<strong>Output:</strong> &quot;and I quote: \&quot;...\&quot;&quot;
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> text = &quot;Stay home! Practice on Leetcode :)&quot;
+<strong>Output:</strong> &quot;Stay home! Practice on Leetcode :)&quot;
+</pre>
+
+<p><strong>Example 4:</strong></p>
+
+<pre>
+<strong>Input:</strong> text = &quot;x &amp;gt; y &amp;amp;&amp;amp; x &amp;lt; y is always false&quot;
+<strong>Output:</strong> &quot;x &gt; y &amp;&amp; x &lt; y is always false&quot;
+</pre>
+
+<p><strong>Example 5:</strong></p>
+
+<pre>
+<strong>Input:</strong> text = &quot;leetcode.com&amp;frasl;problemset&amp;frasl;all&quot;
+<strong>Output:</strong> &quot;leetcode.com/problemset/all&quot;
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= text.length &lt;= 10^5</code></li>
+	<li>The string may contain any possible characters out of all the 256&nbsp;ASCII characters.</li>
+</ul>
+
+### Related Topics
+  [[Stack](../../tag/stack/README.md)]
+  [[String](../../tag/string/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+Search the string for all the occurrences of the character '&'.
+</details>
+
+<details>
+<summary>Hint 2</summary>
+For every '&' check if it matches an HTML entity by checking the ';' character and if entity found replace it in the answer.
+</details>

problems/last-stone-weight/README.md

@@ -11,9 +11,9 @@
 
 ## [1046. Last Stone Weight (Easy)](https://leetcode.com/problems/last-stone-weight "最后一块石头的重量")
 
-<p>We have a collection of rocks, each rock has a positive integer weight.</p>
+<p>We have a collection of stones, each stone&nbsp;has a positive integer weight.</p>
 
-<p>Each turn, we choose the two <strong>heaviest</strong>&nbsp;rocks&nbsp;and smash them together.&nbsp; Suppose the stones have weights <code>x</code> and <code>y</code> with <code>x &lt;= y</code>.&nbsp; The result of this smash is:</p>
+<p>Each turn, we choose the two <strong>heaviest</strong>&nbsp;stones&nbsp;and smash them together.&nbsp; Suppose the stones have weights <code>x</code> and <code>y</code> with <code>x &lt;= y</code>.&nbsp; The result of this smash is:</p>
 
 <ul>
 	<li>If <code>x == y</code>, both stones are totally destroyed;</li>

problems/merge-k-sorted-lists/README.md

@@ -26,9 +26,9 @@
 </pre>
 
 ### Related Topics
+  [[Heap](../../tag/heap/README.md)]
   [[Linked List](../../tag/linked-list/README.md)]
   [[Divide and Conquer](../../tag/divide-and-conquer/README.md)]
-  [[Heap](../../tag/heap/README.md)]
 
 ### Similar Questions
   1. [Merge Two Sorted Lists](../merge-two-sorted-lists) (Easy)

problems/number-of-ways-to-paint-n-3-grid/README.md

@@ -0,0 +1,79 @@
+<!--|This file generated by command(leetcode description); DO NOT EDIT.    |-->
+<!--+----------------------------------------------------------------------+-->
+<!--|@author    openset <[email protected]>                           |-->
+<!--|@link      https://github.com/openset                                 |-->
+<!--|@home      https://github.com/openset/leetcode                        |-->
+<!--+----------------------------------------------------------------------+-->
+
+[< Previous](../html-entity-parser "HTML Entity Parser")
+　　　　　　　　　　　　　　　　
+Next >
+
+## [1411. Number of Ways to Paint N × 3 Grid (Hard)](https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid "给 N x 3 网格图涂色的方案数")
+
+<p>You have a <code>grid</code> of size <code>n x 3</code> and you want to paint each cell of the grid with exactly&nbsp;one of the three colours: <strong>Red</strong>, <strong>Yellow</strong> or <strong>Green</strong>&nbsp;while making sure that no two adjacent cells have&nbsp;the same colour (i.e no two cells that share vertical or horizontal sides have the same colour).</p>
+
+<p>You are given <code>n</code> the number of rows of the grid.</p>
+
+<p>Return <em>the number of ways</em> you can paint this <code>grid</code>. As the answer may grow large, the answer <strong>must be</strong> computed modulo&nbsp;<code>10^9 + 7</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> n = 1
+<strong>Output:</strong> 12
+<strong>Explanation:</strong> There are 12 possible way to paint the grid as shown:
+<img alt="" src="https://assets.leetcode.com/uploads/2020/03/26/e1.png" style="width: 450px; height: 289px;" />
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> n = 2
+<strong>Output:</strong> 54
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> n = 3
+<strong>Output:</strong> 246
+</pre>
+
+<p><strong>Example 4:</strong></p>
+
+<pre>
+<strong>Input:</strong> n = 7
+<strong>Output:</strong> 106494
+</pre>
+
+<p><strong>Example 5:</strong></p>
+
+<pre>
+<strong>Input:</strong> n = 5000
+<strong>Output:</strong> 30228214
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>n == grid.length</code></li>
+	<li><code>grid[i].length == 3</code></li>
+	<li><code>1 &lt;= n &lt;= 5000</code></li>
+</ul>
+
+### Related Topics
+  [[Dynamic Programming](../../tag/dynamic-programming/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+We will use Dynamic programming approach. we will try all possible configuration.
+</details>
+
+<details>
+<summary>Hint 2</summary>
+Let dp[idx][prev1col][prev2col][prev3col] be the number of ways to color the rows of the grid from idx to n-1 keeping in mind that the previous row (idx - 1) has colors prev1col, prev2col and prev3col. Build the dp array to get the answer.
+</details>

problems/queries-on-a-permutation-with-key/README.md

@@ -0,0 +1,72 @@
+<!--|This file generated by command(leetcode description); DO NOT EDIT.    |-->
+<!--+----------------------------------------------------------------------+-->
+<!--|@author    openset <[email protected]>                           |-->
+<!--|@link      https://github.com/openset                                 |-->
+<!--|@home      https://github.com/openset/leetcode                        |-->
+<!--+----------------------------------------------------------------------+-->
+
+[< Previous](../string-matching-in-an-array "String Matching in an Array")
+　　　　　　　　　　　　　　　　
+[Next >](../html-entity-parser "HTML Entity Parser")
+
+## [1409. Queries on a Permutation With Key (Medium)](https://leetcode.com/problems/queries-on-a-permutation-with-key "查询带键的排列")
+
+<p>Given the array <code>queries</code> of positive integers between <code>1</code> and <code>m</code>, you have to process all <code>queries[i]</code> (from <code>i=0</code> to <code>i=queries.length-1</code>) according to the following rules:</p>
+
+<ul>
+	<li>In the beginning, you have the permutation <code>P=[1,2,3,...,m]</code>.</li>
+	<li>For the current <code>i</code>, find the position of <code>queries[i]</code> in the permutation <code>P</code> (<strong>indexing from 0</strong>) and then move this at the beginning of the permutation <code>P.</code>&nbsp;Notice that the position of <code>queries[i]</code> in <code>P</code> is the result for <code>queries[i]</code>.</li>
+</ul>
+
+<p>Return an array containing the result for the given <code>queries</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> queries = [3,1,2,1], m = 5
+<strong>Output:</strong> [2,1,2,1] 
+<strong>Explanation:</strong> The queries are processed as follow: 
+For i=0: queries[i]=3, P=[1,2,3,4,5], position of 3 in P is <strong>2</strong>, then we move 3 to the beginning of P resulting in P=[3,1,2,4,5]. 
+For i=1: queries[i]=1, P=[3,1,2,4,5], position of 1 in P is <strong>1</strong>, then we move 1 to the beginning of P resulting in P=[1,3,2,4,5]. 
+For i=2: queries[i]=2, P=[1,3,2,4,5], position of 2 in P is <strong>2</strong>, then we move 2 to the beginning of P resulting in P=[2,1,3,4,5]. 
+For i=3: queries[i]=1, P=[2,1,3,4,5], position of 1 in P is <strong>1</strong>, then we move 1 to the beginning of P resulting in P=[1,2,3,4,5]. 
+Therefore, the array containing the result is [2,1,2,1].  
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> queries = [4,1,2,2], m = 4
+<strong>Output:</strong> [3,1,2,0]
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> queries = [7,5,5,8,3], m = 8
+<strong>Output:</strong> [6,5,0,7,5]
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= m &lt;= 10^3</code></li>
+	<li><code>1 &lt;= queries.length &lt;= m</code></li>
+	<li><code>1 &lt;= queries[i] &lt;= m</code></li>
+</ul>
+
+### Related Topics
+  [[Array](../../tag/array/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+Create the permutation P=[1,2,...,m], it could be a list for example.
+</details>
+
+<details>
+<summary>Hint 2</summary>
+For each i, find the position of queries[i] with a simple scan over P and then move this to the beginning.
+</details>

problems/rotting-oranges/README.md

@@ -9,7 +9,7 @@
 
 [Next >](../minimum-number-of-k-consecutive-bit-flips "Minimum Number of K Consecutive Bit Flips")
 
-## [994. Rotting Oranges (Easy)](https://leetcode.com/problems/rotting-oranges "腐烂的橘子")
+## [994. Rotting Oranges (Medium)](https://leetcode.com/problems/rotting-oranges "腐烂的橘子")
 
 <p>In a given grid, each cell can have one of three&nbsp;values:</p>
 

problems/stone-game-iii/README.md

@@ -7,7 +7,7 @@
 
 [< Previous](../longest-happy-string "Longest Happy String")
 
-Next >
+[Next >](../top-travellers "Top Travellers")
 
 ## [1406. Stone Game III (Hard)](https://leetcode.com/problems/stone-game-iii "石子游戏 III")