A: new

Author: Shuo

README.md

@@ -70,6 +70,16 @@ LeetCode Problems' Solutions
 
 | # | Title | Solution | Difficulty |
 | :-: | - | - | :-: |
+| <span id="1579">1579</span> | [Remove Max Number of Edges to Keep Graph Fully Traversable](https://leetcode.com/problems/remove-max-number-of-edges-to-keep-graph-fully-traversable "保证图可完全遍历") | [Go](problems/remove-max-number-of-edges-to-keep-graph-fully-traversable) | Hard |
+| <span id="1578">1578</span> | [Minimum Deletion Cost to Avoid Repeating Letters](https://leetcode.com/problems/minimum-deletion-cost-to-avoid-repeating-letters "避免重复字母的最小删除成本") | [Go](problems/minimum-deletion-cost-to-avoid-repeating-letters) | Medium |
+| <span id="1577">1577</span> | [Number of Ways Where Square of Number Is Equal to Product of Two Numbers](https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers "数的平方等于两数乘积的方法数") | [Go](problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers) | Medium |
+| <span id="1576">1576</span> | [Replace All ?'s to Avoid Consecutive Repeating Characters](https://leetcode.com/problems/replace-all-s-to-avoid-consecutive-repeating-characters "替换所有的问号") | [Go](problems/replace-all-s-to-avoid-consecutive-repeating-characters) | Easy |
+| <span id="1575">1575</span> | [Count All Possible Routes](https://leetcode.com/problems/count-all-possible-routes "统计所有可行路径") | [Go](problems/count-all-possible-routes) | Hard |
+| <span id="1574">1574</span> | [Shortest Subarray to be Removed to Make Array Sorted](https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted "删除最短的子数组使剩余数组有序") | [Go](problems/shortest-subarray-to-be-removed-to-make-array-sorted) | Medium |
+| <span id="1573">1573</span> | [Number of Ways to Split a String](https://leetcode.com/problems/number-of-ways-to-split-a-string "分割字符串的方案数") | [Go](problems/number-of-ways-to-split-a-string) | Medium |
+| <span id="1572">1572</span> | [Matrix Diagonal Sum](https://leetcode.com/problems/matrix-diagonal-sum "矩阵对角线元素的和") | [Go](problems/matrix-diagonal-sum) | Easy |
+| <span id="1571">1571</span> | [Warehouse Manager](https://leetcode.com/problems/warehouse-manager) 🔒 | [MySQL](problems/warehouse-manager) | Easy |
+| <span id="1570">1570</span> | [Dot Product of Two Sparse Vectors](https://leetcode.com/problems/dot-product-of-two-sparse-vectors) 🔒 | [Go](problems/dot-product-of-two-sparse-vectors) | Medium |
 | <span id="1569">1569</span> | [Number of Ways to Reorder Array to Get Same BST](https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bst "将子数组重新排序得到同一个二叉查找树的方案数") | [Go](problems/number-of-ways-to-reorder-array-to-get-same-bst) | Hard |
 | <span id="1568">1568</span> | [Minimum Number of Days to Disconnect Island](https://leetcode.com/problems/minimum-number-of-days-to-disconnect-island "使陆地分离的最少天数") | [Go](problems/minimum-number-of-days-to-disconnect-island) | Hard |
 | <span id="1567">1567</span> | [Maximum Length of Subarray With Positive Product](https://leetcode.com/problems/maximum-length-of-subarray-with-positive-product "乘积为正数的最长子数组长度") | [Go](problems/maximum-length-of-subarray-with-positive-product) | Medium |

problems/3sum/README.md

@@ -13,21 +13,26 @@
 
 <p>Given an array <code>nums</code> of <em>n</em> integers, are there elements <em>a</em>, <em>b</em>, <em>c</em> in <code>nums</code> such that <em>a</em> + <em>b</em> + <em>c</em> = 0? Find all unique triplets in the array which gives the sum of zero.</p>
 
-<p><strong>Note:</strong></p>
-
-<p>The solution set must not contain duplicate triplets.</p>
-
-<p><strong>Example:</strong></p>
-
-<pre>
-Given array nums = [-1, 0, 1, 2, -1, -4],
-
-A solution set is:
-[
- [-1, 0, 1],
- [-1, -1, 2]
-]
+<p>Notice that the solution set must not contain duplicate triplets.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+<pre><strong>Input:</strong> nums = [-1,0,1,2,-1,-4]
+<strong>Output:</strong> [[-1,-1,2],[-1,0,1]]
+</pre><p><strong>Example 2:</strong></p>
+<pre><strong>Input:</strong> nums = []
+<strong>Output:</strong> []
+</pre><p><strong>Example 3:</strong></p>
+<pre><strong>Input:</strong> nums = [0]
+<strong>Output:</strong> []
 </pre>
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+<li><code>0 &lt;= nums.length &lt;= 3000</code></li>
+<li><code>-10<sup>5</sup> &lt;= nums[i] &lt;= 10<sup>5</sup></code></li>
+</ul>
 
 ### Related Topics
  [[Array](../../tag/array/README.md)]

problems/contains-duplicate-iii/README.md

@@ -13,32 +13,26 @@
 
 <p>Given an array of integers, find out whether there are two distinct indices <i>i</i> and <i>j</i> in the array such that the <b>absolute</b> difference between <b>nums[i]</b> and <b>nums[j]</b> is at most <i>t</i> and the <b>absolute</b> difference between <i>i</i> and <i>j</i> is at most <i>k</i>.</p>
 
-<div>
+<p>&nbsp;</p>
 <p><strong>Example 1:</strong></p>
-
-<pre>
-<strong>Input: </strong>nums = <span id="example-input-1-1">[1,2,3,1]</span>, k = <span id="example-input-1-2">3</span>, t = <span id="example-input-1-3">0</span>
-<strong>Output: </strong><span id="example-output-1">true</span>
-</pre>
-
-<div>
-<p><strong>Example 2:</strong></p>
-
-<pre>
-<strong>Input: </strong>nums = <span id="example-input-2-1">[1,0,1,1]</span>, k = <span id="example-input-2-2">1</span>, t = <span id="example-input-2-3">2</span>
-<strong>Output: </strong><span id="example-output-2">true</span>
-</pre>
-
-<div>
-<p><strong>Example 3:</strong></p>
-
-<pre>
-<strong>Input: </strong>nums = <span id="example-input-3-1">[1,5,9,1,5,9]</span>, k = <span id="example-input-3-2">2</span>, t = <span id="example-input-3-3">3</span>
-<strong>Output: </strong><span id="example-output-3">false</span>
+<pre><strong>Input:</strong> nums = [1,2,3,1], k = 3, t = 0
+<strong>Output:</strong> true
+</pre><p><strong>Example 2:</strong></p>
+<pre><strong>Input:</strong> nums = [1,0,1,1], k = 1, t = 2
+<strong>Output:</strong> true
+</pre><p><strong>Example 3:</strong></p>
+<pre><strong>Input:</strong> nums = [1,5,9,1,5,9], k = 2, t = 3
+<strong>Output:</strong> false
 </pre>
-</div>
-</div>
-</div>
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+<li><code>0 &lt;= nums.length &lt;= 2 * 10<sup>4</sup></code></li>
+<li><code>-2<sup>31</sup> &lt;= nums[i]&nbsp;&lt;= 2<sup>31</sup> - 1</code></li>
+<li><code>0 &lt;= k &lt;= 10<sup>4</sup></code></li>
+<li><code>0 &lt;= t &lt;= 2<sup>31</sup> - 1</code></li>
+</ul>
 
 ### Related Topics
  [[Sort](../../tag/sort/README.md)]

problems/convert-sorted-list-to-binary-search-tree/README.md

@@ -49,7 +49,7 @@
 <p><strong>Constraints:</strong></p>
 
 <ul>
-<li>The numner of nodes in <code>head</code> is in the range <code>[0, 2 * 10^4]</code>.</li>
+<li>The number of nodes in <code>head</code> is in the range <code>[0, 2 * 10<sup>4</sup>]</code>.</li>
 <li><code>-10^5 &lt;= Node.val &lt;= 10^5</code></li>
 </ul>
 

problems/count-all-possible-routes/README.md

@@ -0,0 +1,95 @@
+<!--|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](../shortest-subarray-to-be-removed-to-make-array-sorted "Shortest Subarray to be Removed to Make Array Sorted")
+　　　　　　　　　　　　　　　　
+[Next >](../replace-all-s-to-avoid-consecutive-repeating-characters "Replace All ?'s to Avoid Consecutive Repeating Characters")
+
+## [1575. Count All Possible Routes (Hard)](https://leetcode.com/problems/count-all-possible-routes "统计所有可行路径")
+
+<p>You are given an array of <strong>distinct</strong> positive integers locations&nbsp;where <code>locations[i]</code> represents the position of city <code>i</code>. You are also given&nbsp;integers&nbsp;<code>start</code>,&nbsp;<code>finish</code>&nbsp;and&nbsp;<code>fuel</code>&nbsp;representing the starting city, ending city, and the initial amount of fuel you have, respectively.</p>
+
+<p>At each step, if you are at city&nbsp;<code>i</code>, you can pick any city&nbsp;<code>j</code>&nbsp;such that <code>j != i</code>&nbsp;and&nbsp;<code>0 &lt;= j &lt; locations.length</code>&nbsp;and move to city <code>j</code>.&nbsp;Moving from city <code>i</code> to city <code>j</code> reduces the amount of fuel you have by&nbsp;<code>|locations[i] - locations[j]|</code>.&nbsp;Please notice that <code>|x|</code>&nbsp;denotes the absolute value of <code>x</code>.</p>
+
+<p>Notice that&nbsp;<code>fuel</code>&nbsp;<strong>cannot</strong> become negative at any point in time, and that you are <strong>allowed</strong> to visit any city more than once (including <code>start</code>&nbsp;and&nbsp;<code>finish</code>).</p>
+
+<p>Return <em>the count of all possible routes from&nbsp;</em><code>start</code>&nbsp;<em>to</em>&nbsp;<code>finish</code>.</p>
+
+<p>Since the answer&nbsp;may be too large,&nbsp;return it modulo&nbsp;<code>10^9 + 7</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> locations = [2,3,6,8,4], start = 1, finish = 3, fuel = 5
+<strong>Output:</strong> 4
+<strong>Explanation:</strong>&nbsp;The following are all possible routes, each uses 5 units of fuel:
+1 -&gt; 3
+1 -&gt; 2 -&gt; 3
+1 -&gt; 4 -&gt; 3
+1 -&gt; 4 -&gt; 2 -&gt; 3
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> locations = [4,3,1], start = 1, finish = 0, fuel = 6
+<strong>Output:</strong> 5
+<strong>Explanation: </strong>The following are all possible routes:
+1 -&gt; 0, used fuel = 1
+1 -&gt; 2 -&gt; 0, used fuel = 5
+1 -&gt; 2 -&gt; 1 -&gt; 0, used fuel = 5
+1 -&gt; 0 -&gt; 1 -&gt; 0, used fuel = 3
+1 -&gt; 0 -&gt; 1 -&gt; 0 -&gt; 1 -&gt; 0, used fuel = 5
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> locations = [5,2,1], start = 0, finish = 2, fuel = 3
+<strong>Output:</strong> 0
+<b>Explanation: </b>It&#39;s impossible to get from 0 to 2 using only 3 units of fuel since the shortest route needs 4 units of fuel.</pre>
+
+<p><strong>Example 4:</strong></p>
+
+<pre>
+<strong>Input:</strong> locations = [2,1,5], start = 0, finish = 0, fuel = 3
+<strong>Output:</strong> 2
+<strong>Explanation:</strong>&nbsp;There are two possible routes, 0 and 0 -&gt; 1 -&gt; 0.</pre>
+
+<p><strong>Example 5:</strong></p>
+
+<pre>
+<strong>Input:</strong> locations = [1,2,3], start = 0, finish = 2, fuel = 40
+<strong>Output:</strong> 615088286
+<strong>Explanation: </strong>The total number of possible routes is 2615088300. Taking this number modulo 10^9 + 7 gives us 615088286.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+<li><code>2 &lt;= locations.length &lt;= 100</code></li>
+<li><code>1 &lt;= locations[i] &lt;= 10^9</code></li>
+<li>All integers in&nbsp;<code>locations</code>&nbsp;are&nbsp;<strong>distinct</strong>.</li>
+<li><code>0 &lt;= start, finish &lt;&nbsp;locations.length</code></li>
+<li><code><font face="monospace">1 &lt;= fuel &lt;= 200</font></code></li>
+</ul>
+
+### Related Topics
+ [[Dynamic Programming](../../tag/dynamic-programming/README.md)]
+
+### Hints
+<details>
+<summary>Hint 1</summary>
+Use dynamic programming to solve this problem with each state defined by the city index and fuel left.
+</details>
+
+<details>
+<summary>Hint 2</summary>
+Since the array contains distinct integers fuel will always be spent in each move and so there can be no cycles.
+</details>

problems/delete-node-in-a-bst/README.md

@@ -13,45 +13,52 @@
 
 <p>Given a root node reference of a BST and a key, delete the node with the given key in the BST. Return the root node reference (possibly updated) of the BST.</p>
 
-<p>Basically, the deletion can be divided into two stages:
+<p>Basically, the deletion can be divided into two stages:</p>
+
 <ol>
-<li>Search for a node to remove.</li>
-<li>If the node is found, delete the node.</li>
+<li>Search for a node to remove.</li>
+<li>If the node is found, delete the node.</li>
 </ol>
-</p>
 
-<p><b>Note:</b> Time complexity should be O(height of tree).</p>
+<p><b>Follow up:</b>&nbsp;Can you solve it with time complexity <code>O(height of tree)</code>?</p>
 
-<p><b>Example:</b>
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+<img alt="" src="https://assets.leetcode.com/uploads/2020/09/04/del_node_1.jpg" style="width: 800px; height: 214px;" />
 <pre>
-root = [5,3,6,2,4,null,7]
-key = 3
+<strong>Input:</strong> root = [5,3,6,2,4,null,7], key = 3
+<strong>Output:</strong> [5,4,6,2,null,null,7]
+<strong>Explanation:</strong> Given key to delete is 3. So we find the node with value 3 and delete it.
+One valid answer is [5,4,6,2,null,null,7], shown in the above BST.
+Please notice that another valid answer is [5,2,6,null,4,null,7] and it&#39;s also accepted.
+<img alt="" src="https://assets.leetcode.com/uploads/2020/09/04/del_node_supp.jpg" style="width: 350px; height: 255px;" />
+</pre>
 
- 5
- / \
- 3 6
- / \ \
-2 4 7
+<p><strong>Example 2:</strong></p>
 
-Given key to delete is 3. So we find the node with value 3 and delete it.
+<pre>
+<strong>Input:</strong> root = [5,3,6,2,4,null,7], key = 0
+<strong>Output:</strong> [5,3,6,2,4,null,7]
+<strong>Explanation:</strong> The tree does not contain a node with value = 0.
+</pre>
 
-One valid answer is [5,4,6,2,null,null,7], shown in the following BST.
+<p><strong>Example 3:</strong></p>
 
- 5
- / \
- 4 6
- / \
-2 7
+<pre>
+<strong>Input:</strong> root = [], key = 0
+<strong>Output:</strong> []
+</pre>
 
-Another valid answer is [5,2,6,null,4,null,7].
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
 
- 5
- / \
- 2 6
- \ \
- 4 7
-</pre>
-</p>
+<ul>
+<li>The number of nodes in the tree is in the range <code>[0, 10<sup>4</sup>]</code>.</li>
+<li><code>-10<sup>5</sup> &lt;= Node.val &lt;= 10<sup>5</sup></code></li>
+<li>Each node has a <strong>unique</strong> value.</li>
+<li><code>root</code> is a valid binary search tree.</li>
+<li><code>-10<sup>5</sup> &lt;= key &lt;= 10<sup>5</sup></code></li>
+</ul>
 
 ### Related Topics
  [[Tree](../../tag/tree/README.md)]

problems/delete-node-in-a-linked-list/README.md

@@ -11,39 +11,56 @@
 
 ## [237. Delete Node in a Linked List (Easy)](https://leetcode.com/problems/delete-node-in-a-linked-list "删除链表中的节点")
 
-<p>Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.</p>
+<p>Write a function to <strong>delete a node</strong> in a singly-linked list. You will <strong>not</strong> be given access to the <code>head</code> of the list, instead you will be given access to <strong>the node to be deleted</strong> directly.</p>
 
-<p>Given linked list --&nbsp;head =&nbsp;[4,5,1,9], which looks like following:</p>
-
-<p><img alt="" src="https://assets.leetcode.com/uploads/2018/12/28/237_example.png" style="margin-top: 5px; margin-bottom: 5px; width: 300px; height: 49px;" /></p>
+<p>It is <strong>guaranteed</strong> that the node to be deleted is <strong>not a tail node</strong> in the list.</p>
 
 <p>&nbsp;</p>
-
 <p><strong>Example 1:</strong></p>
-
+<img alt="" src="https://assets.leetcode.com/uploads/2020/09/01/node1.jpg" style="width: 450px; height: 322px;" />
 <pre>
 <strong>Input:</strong> head = [4,5,1,9], node = 5
 <strong>Output:</strong> [4,1,9]
 <strong>Explanation: </strong>You are given the second node with value 5, the linked list should become 4 -&gt; 1 -&gt; 9 after calling your function.
 </pre>
 
 <p><strong>Example 2:</strong></p>
-
+<img alt="" src="https://assets.leetcode.com/uploads/2020/09/01/node2.jpg" style="width: 450px; height: 354px;" />
 <pre>
 <strong>Input:</strong> head = [4,5,1,9], node = 1
 <strong>Output:</strong> [4,5,9]
 <strong>Explanation: </strong>You are given the third node with value 1, the linked list should become 4 -&gt; 5 -&gt; 9 after calling your function.
 </pre>
 
-<p>&nbsp;</p>
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> head = [1,2,3,4], node = 3
+<strong>Output:</strong> [1,2,4]
+</pre>
+
+<p><strong>Example 4:</strong></p>
 
-<p><strong>Note:</strong></p>
+<pre>
+<strong>Input:</strong> head = [0,1], node = 0
+<strong>Output:</strong> [1]
+</pre>
+
+<p><strong>Example 5:</strong></p>
+
+<pre>
+<strong>Input:</strong> head = [-3,5,-99], node = -3
+<strong>Output:</strong> [5,-99]
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
 
 <ul>
-<li>The linked list will have at least two elements.</li>
-<li>All of the nodes&#39; values will be unique.</li>
-<li>The given node&nbsp;will not be the tail and it will always be a valid node of the linked list.</li>
-<li>Do not return anything from your function.</li>
+<li>The number of the nodes in the given list is in the range <code>[2, 1000]</code>.</li>
+<li><code>-1000 &lt;= Node.val &lt;= 1000</code></li>
+<li>The value of each node in the list is <strong>unique</strong>.</li>
+<li>The <code>node</code> to be deleted is <strong>in the list</strong> and is <strong>not a tail</strong> node</li>
 </ul>
 
 ### Related Topics

problems/design-add-and-search-words-data-structure/README.md

@@ -11,14 +11,14 @@
 
 ## [211. Design Add and Search Words Data Structure (Medium)](https://leetcode.com/problems/design-add-and-search-words-data-structure "添加与搜索单词 - 数据结构设计")
 
-<p>You should design a data structure that supports adding new words and finding if a string matches any previously added string.</p>
+<p>Design a data structure that supports adding new words and finding if a string matches any previously added string.</p>
 
 <p>Implement the <code>WordDictionary</code> class:</p>
 
 <ul>
 <li><code>WordDictionary()</code>&nbsp;Initializes the object.</li>
-<li><code>void addWord(word)</code> adds <code>word</code> to the data structure, it can be matched later.</li>
-<li><code>bool search(word)</code>&nbsp;returns <code>true</code> if there is any string in the data structure that matches <code>word</code>&nbsp;or <code>false</code> otherwise. <code>word</code> may contain dots <code>&#39;.&#39;</code> where dots can be matched with any letter.</li>
+<li><code>void addWord(word)</code> Adds <code>word</code> to the data structure, it can be matched later.</li>
+<li><code>bool search(word)</code>&nbsp;Returns <code>true</code> if there is any string in the data structure that matches <code>word</code>&nbsp;or <code>false</code> otherwise. <code>word</code> may contain dots <code>&#39;.&#39;</code> where dots can be matched with any letter.</li>
 </ul>
 
 <p>&nbsp;</p>
@@ -48,8 +48,8 @@ wordDictionary.search(&quot;b..&quot;); // return True
 <ul>
 <li><code>1 &lt;= word.length &lt;= 500</code></li>
 <li><code>word</code> in <code>addWord</code> consists lower-case English letters.</li>
-<li><code>word</code> in <code>search</code> consist of&nbsp; &#39;.&#39; or lower-case English letters.</li>
-<li>At most <code>50000</code>&nbsp;calls will be made to <code>addWord</code>&nbsp;and <code>search</code> .</li>
+<li><code>word</code> in <code>search</code> consist of&nbsp; <code>&#39;.&#39;</code> or lower-case English letters.</li>
+<li>At most <code>50000</code>&nbsp;calls will be made to <code>addWord</code>&nbsp;and <code>search</code>.</li>
 </ul>
 
 ### Related Topics