Merge pull request #761 from openset/develop

Add: new

Author: Shuo

README.md

@@ -62,6 +62,7 @@ LeetCode Problems' Solutions
 
 | # | Title | Solution | Difficulty |
 | :-: | - | - | :-: |
+| <span id="1321">1321</span> | [Restaurant Growth](https://leetcode.com/problems/restaurant-growth) 🔒 | [MySQL](problems/restaurant-growth) | Medium |
 | <span id="1320">1320</span> | [Minimum Distance to Type a Word Using Two Fingers](https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers "二指输入的的最小距离") | [Go](problems/minimum-distance-to-type-a-word-using-two-fingers) | Hard |
 | <span id="1319">1319</span> | [Number of Operations to Make Network Connected](https://leetcode.com/problems/number-of-operations-to-make-network-connected "连通网络的操作次数") | [Go](problems/number-of-operations-to-make-network-connected) | Medium |
 | <span id="1318">1318</span> | [Minimum Flips to Make a OR b Equal to c](https://leetcode.com/problems/minimum-flips-to-make-a-or-b-equal-to-c "或运算的最小翻转次数") | [Go](problems/minimum-flips-to-make-a-or-b-equal-to-c) | Medium |
@@ -233,7 +234,7 @@ LeetCode Problems' Solutions
 | <span id="1152">1152</span> | [Analyze User Website Visit Pattern](https://leetcode.com/problems/analyze-user-website-visit-pattern "用户网站访问行为分析") 🔒 | [Go](problems/analyze-user-website-visit-pattern) | Medium |
 | <span id="1151">1151</span> | [Minimum Swaps to Group All 1's Together](https://leetcode.com/problems/minimum-swaps-to-group-all-1s-together "最少交换次数来组合所有的 1") 🔒 | [Go](problems/minimum-swaps-to-group-all-1s-together) | Medium |
 | <span id="1150">1150</span> | [Check If a Number Is Majority Element in a Sorted Array](https://leetcode.com/problems/check-if-a-number-is-majority-element-in-a-sorted-array "检查一个数是否在数组中占绝大多数") 🔒 | [Go](problems/check-if-a-number-is-majority-element-in-a-sorted-array) | Easy |
-| <span id="1149">1149</span> | [Article Views II](https://leetcode.com/problems/article-views-ii) 🔒 | [MySQL](problems/article-views-ii) | Medium |
+| <span id="1149">1149</span> | [Article Views II](https://leetcode.com/problems/article-views-ii "文章浏览 II") 🔒 | [MySQL](problems/article-views-ii) | Medium |
 | <span id="1148">1148</span> | [Article Views I](https://leetcode.com/problems/article-views-i "文章浏览 I") 🔒 | [MySQL](problems/article-views-i) | Easy |
 | <span id="1147">1147</span> | [Longest Chunked Palindrome Decomposition](https://leetcode.com/problems/longest-chunked-palindrome-decomposition "段式回文") | [Go](problems/longest-chunked-palindrome-decomposition) | Hard |
 | <span id="1146">1146</span> | [Snapshot Array](https://leetcode.com/problems/snapshot-array "快照数组") | [Go](problems/snapshot-array) | Medium |
@@ -250,7 +251,7 @@ LeetCode Problems' Solutions
 | <span id="1135">1135</span> | [Connecting Cities With Minimum Cost](https://leetcode.com/problems/connecting-cities-with-minimum-cost "最低成本联通所有城市") 🔒 | [Go](problems/connecting-cities-with-minimum-cost) | Medium |
 | <span id="1134">1134</span> | [Armstrong Number](https://leetcode.com/problems/armstrong-number "阿姆斯特朗数") 🔒 | [Go](problems/armstrong-number) | Easy |
 | <span id="1133">1133</span> | [Largest Unique Number](https://leetcode.com/problems/largest-unique-number "最大唯一数") 🔒 | [Go](problems/largest-unique-number) | Easy |
-| <span id="1132">1132</span> | [Reported Posts II](https://leetcode.com/problems/reported-posts-ii) 🔒 | [MySQL](problems/reported-posts-ii) | Medium |
+| <span id="1132">1132</span> | [Reported Posts II](https://leetcode.com/problems/reported-posts-ii "报告的记录 II") 🔒 | [MySQL](problems/reported-posts-ii) | Medium |
 | <span id="1131">1131</span> | [Maximum of Absolute Value Expression](https://leetcode.com/problems/maximum-of-absolute-value-expression "绝对值表达式的最大值") | [Go](problems/maximum-of-absolute-value-expression) | Medium |
 | <span id="1130">1130</span> | [Minimum Cost Tree From Leaf Values](https://leetcode.com/problems/minimum-cost-tree-from-leaf-values "叶值的最小代价生成树") | [Go](problems/minimum-cost-tree-from-leaf-values) | Medium |
 | <span id="1129">1129</span> | [Shortest Path with Alternating Colors](https://leetcode.com/problems/shortest-path-with-alternating-colors "颜色交替的最短路径") | [Go](problems/shortest-path-with-alternating-colors) | Medium |

problems/article-views-ii/README.md

@@ -9,7 +9,7 @@
 
 [Next >](../check-if-a-number-is-majority-element-in-a-sorted-array "Check If a Number Is Majority Element in a Sorted Array")
 
-## [1149. Article Views II (Medium)](https://leetcode.com/problems/article-views-ii "")
+## [1149. Article Views II (Medium)](https://leetcode.com/problems/article-views-ii "文章浏览 II")
 
 <p>Table: <code>Views</code></p>
 

problems/bulb-switcher/README.md

@@ -28,8 +28,8 @@ So you should return 1, because there is only one bulb is on.
 </pre>
 
 ### Related Topics
-  [[Math](../../tag/math/README.md)]
   [[Brainteaser](../../tag/brainteaser/README.md)]
+  [[Math](../../tag/math/README.md)]
 
 ### Similar Questions
   1. [Bulb Switcher II](../bulb-switcher-ii) (Medium)

problems/clone-graph/README.md

@@ -11,35 +11,75 @@
 
 ## [133. Clone Graph (Medium)](https://leetcode.com/problems/clone-graph "克隆图")
 
-<p>Given&nbsp;a reference of a node in a&nbsp;<strong><a href="https://en.wikipedia.org/wiki/Connectivity_(graph_theory)#Connected_graph" target="_blank">connected</a></strong>&nbsp;undirected graph, return a <a href="https://en.wikipedia.org/wiki/Object_copying#Deep_copy" target="_blank"><strong>deep copy</strong></a> (clone) of the graph. Each node in the graph contains a val (<code>int</code>) and a list (<code>List[Node]</code>) of its neighbors.</p>
+<p>Given a reference of a node in a&nbsp;<strong><a href="https://en.wikipedia.org/wiki/Connectivity_(graph_theory)#Connected_graph" target="_blank">connected</a></strong>&nbsp;undirected graph.</p>
+
+<p>Return a <a href="https://en.wikipedia.org/wiki/Object_copying#Deep_copy" target="_blank"><strong>deep copy</strong></a> (clone) of the graph.</p>
+
+<p>Each node in the graph contains a val (<code>int</code>) and a list (<code>List[Node]</code>) of its neighbors.</p>
+
+<pre>
+class Node {
+    public int val;
+    public List&lt;Node&gt; neighbors;
+}
+</pre>
 
 <p>&nbsp;</p>
 
-<p><strong>Example:</strong></p>
+<p><strong>Test case format:</strong></p>
 
-<p><img alt="" src="https://assets.leetcode.com/uploads/2019/11/04/133_clone_graph_question.png" style="width: 500px;height:550px" /></p>
+<p>For simplicity sake, each&nbsp;node&#39;s value is the same as the node&#39;s index (1-indexed). For example, the first node with&nbsp;<code>val = 1</code>, the second node with <code>val = 2</code>, and so on.&nbsp;The graph is represented in the test case using an adjacency list.</p>
 
+<p><b>Adjacency list</b>&nbsp;is a collection of unordered&nbsp;<b>lists</b>&nbsp;used to represent a finite graph. Each&nbsp;list&nbsp;describes the set of neighbors of a node in the graph.</p>
+
+<p>The given node will&nbsp;always be the first node&nbsp;with&nbsp;<code>val = 1</code>. You must return the <strong>copy of the given node</strong> as a reference to the cloned graph.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2019/11/04/133_clone_graph_question.png" style="width: 500px; height: 550px;" />
 <pre>
-<strong>Input:
-</strong>{&quot;$id&quot;:&quot;1&quot;,&quot;neighbors&quot;:[{&quot;$id&quot;:&quot;2&quot;,&quot;neighbors&quot;:[{&quot;$ref&quot;:&quot;1&quot;},{&quot;$id&quot;:&quot;3&quot;,&quot;neighbors&quot;:[{&quot;$ref&quot;:&quot;2&quot;},{&quot;$id&quot;:&quot;4&quot;,&quot;neighbors&quot;:[{&quot;$ref&quot;:&quot;3&quot;},{&quot;$ref&quot;:&quot;1&quot;}],&quot;val&quot;:4}],&quot;val&quot;:3}],&quot;val&quot;:2},{&quot;$ref&quot;:&quot;4&quot;}],&quot;val&quot;:1}
-
-<strong>Explanation:</strong>
-Node 1&#39;s value is 1, and it has two neighbors: Node 2 and 4.
-Node 2&#39;s value is 2, and it has two neighbors: Node 1 and 3.
-Node 3&#39;s value is 3, and it has two neighbors: Node 2 and 4.
-Node 4&#39;s value is 4, and it has two neighbors: Node 1 and 3.
+<strong>Input:</strong> adjList = [[2,4],[1,3],[2,4],[1,3]]
+<strong>Output:</strong> [[2,4],[1,3],[2,4],[1,3]]
+<strong>Explanation:</strong> There are 4 nodes in the graph.
+1st node (val = 1)&#39;s neighbors are 2nd node (val = 2) and 4th node (val = 4).
+2nd node (val = 2)&#39;s neighbors are 1st node (val = 1) and 3rd node (val = 3).
+3rd node (val = 3)&#39;s neighbors are 2nd node (val = 2) and 4th node (val = 4).
+4th node (val = 4)&#39;s neighbors are 1st node (val = 1) and 3rd node (val = 3).
 </pre>
 
-<p>&nbsp;</p>
+<p><strong>Example 2:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2020/01/07/graph.png" style="width: 163px; height: 148px;" />
+<pre>
+<strong>Input:</strong> adjList = [[]]
+<strong>Output:</strong> [[]]
+<strong>Explanation:</strong> Note that the input contains one empty list. The graph consists of only one node with val = 1 and it does not have any neighbors.
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> adjList = []
+<strong>Output:</strong> []
+<strong>Explanation:</strong> This an empty graph, it does not have any nodes.
+</pre>
 
-<p><strong>Note:</strong></p>
+<p><strong>Example 4:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2020/01/07/graph-1.png" style="width: 272px; height: 133px;" />
+<pre>
+<strong>Input:</strong> adjList = [[2],[1]]
+<strong>Output:</strong> [[2],[1]]
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
 
-<ol>
-	<li>The number of nodes will be between 1 and 100.</li>
-	<li>The undirected&nbsp;graph is a <a href="https://en.wikipedia.org/wiki/Graph_(discrete_mathematics)#Simple_graph" target="_blank">simple graph</a>,&nbsp;which means no repeated edges and no self-loops in the graph.</li>
-	<li>Since the graph is undirected, if node <em>p</em>&nbsp;has node <em>q</em>&nbsp;as&nbsp;neighbor, then node <em>q</em>&nbsp;must have node <em>p</em>&nbsp;as neighbor too.</li>
-	<li>You must return the <strong>copy of the given node</strong> as a reference to the cloned graph.</li>
-</ol>
+<ul>
+	<li><code>1 &lt;= Node.val &lt;= 100</code></li>
+	<li><code>Node.val</code> is unique for each node.</li>
+	<li>Number of Nodes will not exceed 100.</li>
+	<li>There is no repeated edges and no self-loops in the graph.</li>
+	<li>The Graph is connected and all nodes can be visited starting from the given node.</li>
+</ul>
 
 ### Related Topics
   [[Depth-first Search](../../tag/depth-first-search/README.md)]

problems/count-of-smaller-numbers-after-self/README.md

@@ -26,11 +26,11 @@ To the right of 1 there is <b>0</b> smaller element.
 </pre>
 
 ### Related Topics
-  [[Binary Search](../../tag/binary-search/README.md)]
-  [[Divide and Conquer](../../tag/divide-and-conquer/README.md)]
   [[Sort](../../tag/sort/README.md)]
   [[Binary Indexed Tree](../../tag/binary-indexed-tree/README.md)]
   [[Segment Tree](../../tag/segment-tree/README.md)]
+  [[Binary Search](../../tag/binary-search/README.md)]
+  [[Divide and Conquer](../../tag/divide-and-conquer/README.md)]
 
 ### Similar Questions
   1. [Count of Range Sum](../count-of-range-sum) (Hard)

problems/create-maximum-number/README.md

@@ -47,8 +47,8 @@ k = <code>3</code>
 </pre>
 
 ### Related Topics
-  [[Dynamic Programming](../../tag/dynamic-programming/README.md)]
   [[Greedy](../../tag/greedy/README.md)]
+  [[Dynamic Programming](../../tag/dynamic-programming/README.md)]
 
 ### Similar Questions
   1. [Remove K Digits](../remove-k-digits) (Medium)

problems/decompress-run-length-encoded-list/README.md

@@ -19,9 +19,15 @@
 
 <p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>
-<pre><strong>Input:</strong> nums = [1,2,3,4]
+
+<pre>
+<strong>Input:</strong> nums = [1,2,3,4]
 <strong>Output:</strong> [2,4,4,4]
+<strong>Explanation:</strong> The first pair [1,2] means we have freq = 1 and val = 2 so we generate the array [2].
+The second pair [3,4] means we have freq = 3 and val = 4 so we generate [4,4,4].
+At the end the concatenation [2] + [4,4,4,4] is [2,4,4,4].
 </pre>
+
 <p>&nbsp;</p>
 <p><strong>Constraints:</strong></p>
 

problems/distinct-echo-substrings/README.md

@@ -11,7 +11,7 @@
 
 ## [1316. Distinct Echo Substrings (Hard)](https://leetcode.com/problems/distinct-echo-substrings "不同的循环子字符串")
 
-<p>Return the number of <strong>distinct</strong> non-empty substrings of <code>text</code>&nbsp;that can be written as the concatenation of some string with itself.</p>
+<p>Return the number of <strong>distinct</strong> non-empty substrings of <code>text</code>&nbsp;that can be written as the concatenation of some string with itself (i.e. it can be written as <code>a + a</code>&nbsp;where <code>a</code> is some string).</p>
 
 <p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>

problems/find-the-team-size/README.md

@@ -11,4 +11,47 @@
 
 ## [1303. Find the Team Size (Easy)](https://leetcode.com/problems/find-the-team-size "求团队人数")
 
+<p>Table: <code>Employee</code></p>
+<pre>
++---------------+---------+
+| Column Name   | Type    |
++---------------+---------+
+| employee_id   | int     |
+| team_id       | int     |
++---------------+---------+
+employee_id is the primary key for this table.
+Each row of this table contains the ID of each employee and their respective team.
+</pre>
 
+Write an SQL query to find the team size of each of the employees.
+
+Return result table in any order.
+
+The query result format is in the following example:
+<pre>
+Employee Table:
++-------------+------------+
+| employee_id | team_id    |
++-------------+------------+
+|     1       |     8      |
+|     2       |     8      |
+|     3       |     8      |
+|     4       |     7      |
+|     5       |     9      |
+|     6       |     9      |
++-------------+------------+
+Result table:
++-------------+------------+
+| employee_id | team_size  |
++-------------+------------+
+|     1       |     3      |
+|     2       |     3      |
+|     3       |     3      |
+|     4       |     1      |
+|     5       |     2      |
+|     6       |     2      |
++-------------+------------+
+Employees with Id 1,2,3 are part of a team with team_id = 8.
+Employees with Id 4 is part of a team with team_id = 7.
+Employees with Id 5,6 are part of a team with team_id = 9.
+</pre>

problems/generalized-abbreviation/README.md

@@ -26,8 +26,8 @@
 <p>&nbsp;</p>
 
 ### Related Topics
-  [[Backtracking](../../tag/backtracking/README.md)]
   [[Bit Manipulation](../../tag/bit-manipulation/README.md)]
+  [[Backtracking](../../tag/backtracking/README.md)]
 
 ### Similar Questions
   1. [Subsets](../subsets) (Medium)

problems/height-checker/README.md

@@ -13,27 +13,20 @@
 
 <p>Students are asked to stand in non-decreasing order of heights for an annual photo.</p>
 
-<p>Return the minimum number of students not standing in the right positions.&nbsp; (This is the number of students that must move in order for all students to be standing in non-decreasing order of height.)</p>
+<p>Return the minimum number of students that must move in order for all students to be standing in non-decreasing order of height.</p>
 
 <p>&nbsp;</p>
-
 <p><strong>Example 1:</strong></p>
-
-<pre>
-<strong>Input: </strong>[1,1,4,2,1,3]
-<strong>Output: </strong>3
-<strong>Explanation: </strong>
-Students with heights 4, 3 and the last 1 are not standing in the right positions.
+<pre><strong>Input:</strong> heights = [1,1,4,2,1,3]
+<strong>Output:</strong> 3
 </pre>
-
 <p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
 
-<p><strong>Note:</strong></p>
-
-<ol>
+<ul>
 	<li><code>1 &lt;= heights.length &lt;= 100</code></li>
 	<li><code>1 &lt;= heights[i] &lt;= 100</code></li>
-</ol>
+</ul>
 
 ### Related Topics
   [[Array](../../tag/array/README.md)]

problems/minimum-distance-to-type-a-word-using-two-fingers/README.md

@@ -7,7 +7,7 @@
 
 [< Previous](../number-of-operations-to-make-network-connected "Number of Operations to Make Network Connected")
 
-Next >
+[Next >](../restaurant-growth "Restaurant Growth")
 
 ## [1320. Minimum Distance to Type a Word Using Two Fingers (Hard)](https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers "二指输入的的最小距离")
 

problems/reported-posts-ii/README.md

@@ -9,7 +9,7 @@
 
 [Next >](../largest-unique-number "Largest Unique Number")
 
-## [1132. Reported Posts II (Medium)](https://leetcode.com/problems/reported-posts-ii "")
+## [1132. Reported Posts II (Medium)](https://leetcode.com/problems/reported-posts-ii "报告的记录 II")
 
 <p>Table: <code>Actions</code></p>
 

problems/restaurant-growth/README.md

@@ -0,0 +1,72 @@
+<!--|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](../minimum-distance-to-type-a-word-using-two-fingers "Minimum Distance to Type a Word Using Two Fingers")
+　　　　　　　　　　　　　　　　
+Next >
+
+## [1321. Restaurant Growth (Medium)](https://leetcode.com/problems/restaurant-growth "")
+
+<p>Table: <code>Customer</code></p>
+<pre>
++---------------+---------+
+| Column Name   | Type    |
++---------------+---------+
+| customer_id   | int     |
+| name          | varchar |
+| visited_on    | date    |
+| amount        | int     |
++---------------+---------+
+(customer_id, visited_on) is the primary key for this table.
+This table contains data about customer transactions in a restaurant.
+visited_on is the date on which the customer with ID (customer_id) have visited the restaurant.
+amount is the total paid by a customer.
+</pre>
+
+You are the restaurant owner and you want to analyze a possible expansion (there will be at least one customer every day).
+
+Write an SQL query to compute moving average of how much customer paid in a 7 days window (current day + 6 days before) .
+
+The query result format is in the following example:
+
+Return result table ordered by visited_on.
+
+average_amount should be rounded to 2 decimal places, all dates are in the format ('YYYY-MM-DD').
+
+<pre>
+Customer table:
++-------------+--------------+--------------+-------------+
+| customer_id | name         | visited_on   | amount      |
++-------------+--------------+--------------+-------------+
+| 1           | Jhon         | 2019-01-01   | 100         |
+| 2           | Daniel       | 2019-01-02   | 110         |
+| 3           | Jade         | 2019-01-03   | 120         |
+| 4           | Khaled       | 2019-01-04   | 130         |
+| 5           | Winston      | 2019-01-05   | 110         | 
+| 6           | Elvis        | 2019-01-06   | 140         | 
+| 7           | Anna         | 2019-01-07   | 150         |
+| 8           | Maria        | 2019-01-08   | 80          |
+| 9           | Jaze         | 2019-01-09   | 110         | 
+| 1           | Jhon         | 2019-01-10   | 130         | 
+| 3           | Jade         | 2019-01-10   | 150         | 
++-------------+--------------+--------------+-------------+
+
+Result table:
++--------------+--------------+----------------+
+| visited_on   | amount       | average_amount |
++--------------+--------------+----------------+
+| 2019-01-07   | 860          | 122.86         |
+| 2019-01-08   | 840          | 120            |
+| 2019-01-09   | 840          | 120            |
+| 2019-01-10   | 1000         | 142.86         |
++--------------+--------------+----------------+
+
+1st moving average from 2019-01-01 to 2019-01-07 has an average_amount of (100 + 110 + 120 + 130 + 110 + 140 + 150)/7 = 122.86
+2nd moving average from 2019-01-02 to 2019-01-08 has an average_amount of (110 + 120 + 130 + 110 + 140 + 150 + 80)/7 = 120
+3rd moving average from 2019-01-03 to 2019-01-09 has an average_amount of (120 + 130 + 110 + 140 + 150 + 80 + 110)/7 = 120
+4th moving average from 2019-01-04 to 2019-01-10 has an average_amount of (130 + 110 + 140 + 150 + 80 + 110 + 130 + 150)/7 = 142.86
+</pre>