A: new

Author: Shuo

Diff for: README.md

@@ -54,7 +54,7 @@
 <p><strong>Constraints:</strong></p>
 
 <ul>
-	<li><code>2 &lt;= asteroids &lt;= 10<sup>4</sup></code></li>
+	<li><code>2 &lt;= asteroids.length&nbsp;&lt;= 10<sup>4</sup></code></li>
 	<li><code>-1000 &lt;= asteroids[i] &lt;= 1000</code></li>
 	<li><code>asteroids[i] != 0</code></li>
 </ul>

Diff for: problems/asteroid-collision/README.md

@@ -9,6 +9,6 @@
 
 [Next >](../maximum-units-on-a-truck "Maximum Units on a Truck")
 
-## [1709. Biggest Window Between Visits (Medium)](https://leetcode.com/problems/biggest-window-between-visits "")
+## [1709. Biggest Window Between Visits (Medium)](https://leetcode.com/problems/biggest-window-between-visits "访问日期之间最大的空档期")
 
 

Diff for: problems/biggest-window-between-visits/README.md

@@ -63,7 +63,10 @@
 </ul>
 
 ### Related Topics
+  [[Tree](../../tag/tree/README.md)]
+  [[Depth-first Search](../../tag/depth-first-search/README.md)]
   [[Binary Search Tree](../../tag/binary-search-tree/README.md)]
+  [[Recursion](../../tag/recursion/README.md)]
 
 ### Hints
 <details>

Diff for: problems/binary-search-tree-to-greater-sum-tree/README.md

@@ -11,9 +11,9 @@
 
 ## [1328. Break a Palindrome (Medium)](https://leetcode.com/problems/break-a-palindrome "破坏回文串")
 
-<p>Given a palindromic string <code>palindrome</code>, replace <strong>exactly one</strong> character by any lowercase English letter so that the string becomes the lexicographically smallest possible string that <strong>isn&#39;t</strong> a palindrome.</p>
+<p>Given a palindromic string <code>palindrome</code>, replace <strong>exactly one</strong> character with any lowercase English letter so that the string becomes the <strong>lexicographically smallest</strong> possible string that is <strong>not</strong> a palindrome.</p>
 
-<p>After doing so, return the final string.&nbsp; If there is no way to do so, return the empty string.</p>
+<p>After doing so, return <em>the final string. If there is no way to do so, return an empty string</em>.</p>
 
 <p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>
@@ -35,7 +35,7 @@
 
 <ul>
 	<li><code>1 &lt;= palindrome.length &lt;= 1000</code></li>
-	<li><code>palindrome</code>&nbsp;consists of only lowercase English letters.</li>
+	<li><code>palindrome</code> consists of only lowercase English letters.</li>
 </ul>
 
 ### Related Topics

Diff for: problems/break-a-palindrome/README.md

@@ -11,28 +11,42 @@
 
 ## [815. Bus Routes (Hard)](https://leetcode.com/problems/bus-routes "公交路线")
 
-<p>We have a list of bus routes. Each <code>routes[i]</code> is a bus route that the i-th bus&nbsp;repeats forever. For example if <code>routes[0] = [1, 5, 7]</code>, this means that the first&nbsp;bus (0-th indexed) travels in the sequence 1-&gt;5-&gt;7-&gt;1-&gt;5-&gt;7-&gt;1-&gt;... forever.</p>
+<p>You are given an array <code>routes</code> representing bus routes where <code>routes[i]</code> is a bus route that the <code>i<sup>th</sup></code> bus repeats forever.</p>
 
-<p>We start at bus stop <code>S</code> (initially not on a bus), and we want to go to bus stop <code>T</code>. Travelling by buses only, what is the least number of buses we must take to reach our destination? Return -1 if it is not possible.</p>
+<ul>
+	<li>For example, if <code>routes[0] = [1, 5, 7]</code>, this means that the <code>0<sup>th</sup></code> bus travels in the sequence <code>1 -&gt; 5 -&gt; 7 -&gt; 1 -&gt; 5 -&gt; 7 -&gt; 1 -&gt; ...</code> forever.</li>
+</ul>
+
+<p>You will start at the bus stop <code>source</code> (You are not on any bus initially), and you want to go to the bus stop <code>target</code>. You can travel between bus stops by buses only.</p>
+
+<p>Return <em>the least number of buses you must take to travel from </em><code>source</code><em> to </em><code>target</code>. Return <code>-1</code> if it is not possible.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
 
 <pre>
-<strong>Example:</strong>
-<strong>Input:</strong> 
-routes = [[1, 2, 7], [3, 6, 7]]
-S = 1
-T = 6
+<strong>Input:</strong> routes = [[1,2,7],[3,6,7]], source = 1, target = 6
 <strong>Output:</strong> 2
-<strong>Explanation:</strong> 
-The best strategy is take the first bus to the bus stop 7, then take the second bus to the bus stop 6.
+<strong>Explanation:</strong> The best strategy is take the first bus to the bus stop 7, then take the second bus to the bus stop 6.
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> routes = [[7,12],[4,5,15],[6],[15,19],[9,12,13]], source = 15, target = 12
+<strong>Output:</strong> -1
 </pre>
 
 <p>&nbsp;</p>
 <p><strong>Constraints:</strong></p>
 
 <ul>
 	<li><code>1 &lt;= routes.length &lt;= 500</code>.</li>
-	<li><code>1 &lt;= routes[i].length &lt;= 10^5</code>.</li>
-	<li><code>0 &lt;= routes[i][j] &lt; 10 ^ 6</code>.</li>
+	<li><code>1 &lt;= routes[i].length &lt;= 10<sup>5</sup></code></li>
+	<li>All the values of <code>routes[i]</code> are <strong>unique</strong>.</li>
+	<li><code>sum(routes[i].length) &lt;= 10<sup>5</sup></code></li>
+	<li><code>0 &lt;= routes[i][j] &lt; 10<sup>6</sup></code></li>
+	<li><code>0 &lt;= source, target &lt; 10<sup>6</sup></code></li>
 </ul>
 
 ### Related Topics

Diff for: problems/bus-routes/README.md

@@ -0,0 +1,84 @@
+<!--|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](../restore-the-array-from-adjacent-pairs "Restore the Array From Adjacent Pairs")
+　　　　　　　　　　　　　　　　
+[Next >](../palindrome-partitioning-iv "Palindrome Partitioning IV")
+
+## [1744. Can You Eat Your Favorite Candy on Your Favorite Day? (Medium)](https://leetcode.com/problems/can-you-eat-your-favorite-candy-on-your-favorite-day "你能在你最喜欢的那天吃到你最喜欢的糖果吗？")
+
+<p>You are given a <strong>(0-indexed)</strong> array of positive integers <code>candiesCount</code> where <code>candiesCount[i]</code> represents the number of candies of the&nbsp;<code>i<sup>th</sup></code>&nbsp;type you have. You are also given a 2D array <code>queries</code> where <code>queries[i] = [favoriteType<sub>i</sub>, favoriteDay<sub>i</sub>, dailyCap<sub>i</sub>]</code>.</p>
+
+<p>You play a game with the following rules:</p>
+
+<ul>
+	<li>You start eating candies on day <code><strong>0</strong></code>.</li>
+	<li>You <b>cannot</b> eat <strong>any</strong> candy of type <code>i</code> unless you have eaten <strong>all</strong> candies of type <code>i - 1</code>.</li>
+	<li>You must eat <strong>at least</strong> <strong>one</strong> candy per day until you have eaten all the candies.</li>
+</ul>
+
+<p>Construct a boolean array <code>answer</code> such that <code>answer.length == queries.length</code> and <code>answer[i]</code> is <code>true</code> if you can eat a candy of type <code>favoriteType<sub>i</sub></code> on day <code>favoriteDay<sub>i</sub></code> without eating <strong>more than</strong> <code>dailyCap<sub>i</sub></code> candies on <strong>any</strong> day, and <code>false</code> otherwise. Note that you can eat different types of candy on the same day, provided that you follow rule 2.</p>
+
+<p>Return <em>the constructed array </em><code>answer</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> candiesCount = [7,4,5,3,8], queries = [[0,2,2],[4,2,4],[2,13,1000000000]]
+<strong>Output:</strong> [true,false,true]
+<strong>Explanation:</strong>
+1- If you eat 2 candies (type 0) on day 0 and 2 candies (type 0) on day 1, you will eat a candy of type 0 on day 2.
+2- You can eat at most 4 candies each day.
+   If you eat 4 candies every day, you will eat 4 candies (type 0) on day 0 and 4 candies (type 0 and type 1) on day 1.
+   On day 2, you can only eat 4 candies (type 1 and type 2), so you cannot eat a candy of type 4 on day 2.
+3- If you eat 1 candy each day, you will eat a candy of type 2 on day 13.
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> candiesCount = [5,2,6,4,1], queries = [[3,1,2],[4,10,3],[3,10,100],[4,100,30],[1,3,1]]
+<strong>Output:</strong> [false,true,true,false,false]
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= candiesCount.length &lt;= 10<sup>5</sup></code></li>
+	<li><code>1 &lt;= candiesCount[i] &lt;= 10<sup>5</sup></code></li>
+	<li><code>1 &lt;= queries.length &lt;= 10<sup>5</sup></code></li>
+	<li><code>queries[i].length == 3</code></li>
+	<li><code>0 &lt;= favoriteType<sub>i</sub> &lt; candiesCount.length</code></li>
+	<li><code>0 &lt;= favoriteDay<sub>i</sub> &lt;= 10<sup>9</sup></code></li>
+	<li><code>1 &lt;= dailyCap<sub>i</sub> &lt;= 10<sup>9</sup></code></li>
+</ul>
+
+### Related Topics
+  [[Math](../../tag/math/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+The query is true if and only if your favorite day is in between the earliest and latest possible days to eat your favorite candy.
+</details>
+
+<details>
+<summary>Hint 2</summary>
+To get the earliest day, you need to eat dailyCap candies every day. To get the latest day, you need to eat 1 candy every day.
+</details>
+
+<details>
+<summary>Hint 3</summary>
+The latest possible day is the total number of candies with a smaller type plus the number of your favorite candy minus 1.
+</details>
+
+<details>
+<summary>Hint 4</summary>
+The earliest possible day that you can eat your favorite candy is the total number of candies with a smaller type divided by dailyCap.
+</details>

Diff for: problems/can-you-eat-your-favorite-candy-on-your-favorite-day/README.md

@@ -9,7 +9,7 @@
 
 [Next >](../number-of-rectangles-that-can-form-the-largest-square "Number Of Rectangles That Can Form The Largest Square")
 
-## [1724. Checking Existence of Edge Length Limited Paths II (Hard)](https://leetcode.com/problems/checking-existence-of-edge-length-limited-paths-ii "")
+## [1724. Checking Existence of Edge Length Limited Paths II (Hard)](https://leetcode.com/problems/checking-existence-of-edge-length-limited-paths-ii "检查边长度限制的路径是否存在 II")
 
 
 

Diff for: problems/checking-existence-of-edge-length-limited-paths-ii/README.md

@@ -11,9 +11,9 @@
 
 ## [472. Concatenated Words (Hard)](https://leetcode.com/problems/concatenated-words "连接词")
 
-<p>Given a list of words (<strong>without duplicates</strong>), please write a program that returns all concatenated words in the given list of words.</p>
+<p>Given an array of strings <code>words</code> (<strong>without duplicates</strong>), return <em>all the <strong>concatenated words</strong> in the given list of</em> <code>words</code>.</p>
 
-<p>A concatenated word is defined as a string that is comprised entirely of at least two shorter words in the given array.</p>
+<p>A <strong>concatenated word</strong> is defined as a string that is comprised entirely of at least two shorter words in the given array.</p>
 
 <p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>

Diff for: problems/concatenated-words/README.md

@@ -64,3 +64,6 @@
 
 ### Related Topics
   [[Tree](../../tag/tree/README.md)]
+  [[Depth-first Search](../../tag/depth-first-search/README.md)]
+  [[Binary Search Tree](../../tag/binary-search-tree/README.md)]
+  [[Recursion](../../tag/recursion/README.md)]

Diff for: problems/convert-bst-to-greater-tree/README.md

@@ -11,17 +11,23 @@
 
 ## [138. Copy List with Random Pointer (Medium)](https://leetcode.com/problems/copy-list-with-random-pointer "复制带随机指针的链表")
 
-<p>A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.</p>
+<p>A linked list of length <code>n</code> is given such that each node contains an additional random pointer, which could point to any node in the list, or <code>null</code>.</p>
 
-<p>Return a <a href="https://en.wikipedia.org/wiki/Object_copying#Deep_copy" target="_blank"><strong>deep copy</strong></a> of the list.</p>
+<p>Construct a <a href="https://en.wikipedia.org/wiki/Object_copying#Deep_copy" target="_blank"><strong>deep copy</strong></a> of the list. The deep copy should consist of exactly <code>n</code> <strong>brand new</strong> nodes, where each new node has its value set to the value of its corresponding original node. Both the <code>next</code> and <code>random</code> pointer of the new nodes should point to new nodes in the copied list such that the pointers in the original list and copied list represent the same list state. <strong>None of the pointers in the new list should point to nodes in the original list</strong>.</p>
 
-<p>The Linked List is represented in the input/output as a list of <code>n</code> nodes. Each node is represented as a pair of <code>[val, random_index]</code> where:</p>
+<p>For example, if there are two nodes <code>X</code> and <code>Y</code> in the original list, where <code>X.random --&gt; Y</code>, then for the corresponding two nodes <code>x</code> and <code>y</code> in the copied list, <code>x.random --&gt; y</code>.</p>
+
+<p>Return <em>the head of the copied linked list</em>.</p>
+
+<p>The linked list is represented in the input/output as a list of <code>n</code> nodes. Each node is represented as a pair of <code>[val, random_index]</code> where:</p>
 
 <ul>
 	<li><code>val</code>: an integer representing <code>Node.val</code></li>
-	<li><code>random_index</code>: the index of the node (range from <code>0</code> to <code>n-1</code>) where random pointer points to, or <code>null</code> if it does not point to any node.</li>
+	<li><code>random_index</code>: the index of the node (range from <code>0</code> to <code>n-1</code>) that the <code>random</code> pointer points to, or <code>null</code> if it does not point to any node.</li>
 </ul>
 
+<p>Your code will <strong>only</strong> be given the <code>head</code> of the original linked list.</p>
+
 <p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>
 <img alt="" src="https://assets.leetcode.com/uploads/2019/12/18/e1.png" style="width: 700px; height: 142px;" />
@@ -51,16 +57,16 @@
 <pre>
 <strong>Input:</strong> head = []
 <strong>Output:</strong> []
-<strong>Explanation:</strong> Given linked list is empty (null pointer), so return null.
+<strong>Explanation:</strong> The given linked list is empty (null pointer), so return null.
 </pre>
 
 <p>&nbsp;</p>
 <p><strong>Constraints:</strong></p>
 
 <ul>
+	<li><code>0 &lt;= n &lt;= 1000</code></li>
 	<li><code>-10000 &lt;= Node.val &lt;= 10000</code></li>
-	<li><code>Node.random</code> is null or pointing to a node in the linked list.</li>
-	<li>The number of nodes will not exceed 1000.</li>
+	<li><code>Node.random</code> is <code>null</code> or is pointing to some node in the linked list.</li>
 </ul>
 
 ### Related Topics

Diff for: problems/copy-list-with-random-pointer/README.md

@@ -9,6 +9,6 @@
 
 [Next >](../calculate-money-in-leetcode-bank "Calculate Money in Leetcode Bank")
 
-## [1715. Count Apples and Oranges (Medium)](https://leetcode.com/problems/count-apples-and-oranges "")
+## [1715. Count Apples and Oranges (Medium)](https://leetcode.com/problems/count-apples-and-oranges "苹果和橘子的个数")
 
 

Diff for: problems/count-apples-and-oranges/README.md

@@ -9,7 +9,7 @@
 
 [Next >](../cherry-pickup-ii "Cherry Pickup II")
 
-## [1462. Course Schedule IV (Medium)](https://leetcode.com/problems/course-schedule-iv "课程安排 IV")
+## [1462. Course Schedule IV (Medium)](https://leetcode.com/problems/course-schedule-iv "课程表 IV")
 
 <p>There are a total of <code>n</code> courses you have to take, labeled from <code>0</code> to <code>n-1</code>.</p>
 

Diff for: problems/course-schedule-iv/README.md

@@ -11,39 +11,42 @@
 
 ## [207. Course Schedule (Medium)](https://leetcode.com/problems/course-schedule "课程表")
 
-<p>There are a total of <code>numCourses</code> courses you have to take, labeled from <code>0</code> to <code>numCourses-1</code>.</p>
+<p>There are a total of <code>numCourses</code> courses you have to take, labeled from <code>0</code> to <code>numCourses - 1</code>. You are given an array <code>prerequisites</code> where <code>prerequisites[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> indicates that you <strong>must</strong> take course <code>b<sub>i</sub></code> first if you want to take course <code>a<sub>i</sub></code>.</p>
 
-<p>Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair: <code>[0,1]</code></p>
+<ul>
+	<li>For example, the pair <code>[0, 1]</code>, indicates that to take course <code>0</code> you have to first take course <code>1</code>.</li>
+</ul>
 
-<p>Given the total number of courses and a list of prerequisite <b>pairs</b>, is it possible for you to finish all courses?</p>
+<p>Return <code>true</code> if you can finish all courses. Otherwise, return <code>false</code>.</p>
 
 <p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>
 
 <pre>
 <strong>Input:</strong> numCourses = 2, prerequisites = [[1,0]]
 <strong>Output:</strong> true
-<strong>Explanation:</strong>&nbsp;There are a total of 2 courses to take. 
-&nbsp;            To take course 1 you should have finished course 0. So it is possible.
+<strong>Explanation:</strong> There are a total of 2 courses to take. 
+To take course 1 you should have finished course 0. So it is possible.
 </pre>
 
 <p><strong>Example 2:</strong></p>
 
 <pre>
 <strong>Input:</strong> numCourses = 2, prerequisites = [[1,0],[0,1]]
 <strong>Output:</strong> false
-<strong>Explanation:</strong>&nbsp;There are a total of 2 courses to take. 
-&nbsp;            To take course 1 you should have finished course 0, and to take course 0 you should
-&nbsp;            also have finished course 1. So it is impossible.
+<strong>Explanation:</strong> There are a total of 2 courses to take. 
+To take course 1 you should have finished course 0, and to take course 0 you should also have finished course 1. So it is impossible.
 </pre>
 
 <p>&nbsp;</p>
 <p><strong>Constraints:</strong></p>
 
 <ul>
-	<li>The input prerequisites is a graph represented by <b>a list of edges</b>, not adjacency matrices. Read more about <a href="https://www.khanacademy.org/computing/computer-science/algorithms/graph-representation/a/representing-graphs" target="_blank">how a graph is represented</a>.</li>
-	<li>You may assume that there are no duplicate edges in the input prerequisites.</li>
-	<li><code>1 &lt;=&nbsp;numCourses &lt;= 10^5</code></li>
+	<li><code>1 &lt;= numCourses &lt;= 10<sup>5</sup></code></li>
+	<li><code>0 &lt;= prerequisites.length &lt;= 5000</code></li>
+	<li><code>prerequisites[i].length == 2</code></li>
+	<li><code>0 &lt;= a<sub>i</sub>, b<sub>i</sub> &lt; numCourses</code></li>
+	<li>All the pairs prerequisites[i] are <strong>unique</strong>.</li>
 </ul>
 
 ### Related Topics