Merge pull request #258 from openset/develop

Update: README

Author: Shuo

README.md

@@ -418,29 +418,29 @@ LeetCode Problems' Solutions
 | <span id="622">622</span> | [Design Circular Queue](https://leetcode.com/problems/design-circular-queue "设计循环队列") | [Go](https://github.com/openset/leetcode/tree/master/problems/design-circular-queue) | Medium |
 | <span id="621">621</span> | [Task Scheduler](https://leetcode.com/problems/task-scheduler "任务调度器") | [Go](https://github.com/openset/leetcode/tree/master/problems/task-scheduler) | Medium |
 | <span id="620">620</span> | [Not Boring Movies](https://leetcode.com/problems/not-boring-movies "有趣的电影") | [MySQL](https://github.com/openset/leetcode/tree/master/problems/not-boring-movies) | Easy |
-| <span id="619">619</span> | [Biggest Single Number](https://leetcode.com/problems/biggest-single-number) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/biggest-single-number) | Easy |
-| <span id="618">618</span> | [Students Report By Geography](https://leetcode.com/problems/students-report-by-geography) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/students-report-by-geography) | Hard |
+| <span id="619">619</span> | [Biggest Single Number](https://leetcode.com/problems/biggest-single-number) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/biggest-single-number) | Easy |
+| <span id="618">618</span> | [Students Report By Geography](https://leetcode.com/problems/students-report-by-geography) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/students-report-by-geography) | Hard |
 | <span id="617">617</span> | [Merge Two Binary Trees](https://leetcode.com/problems/merge-two-binary-trees "合并二叉树") | [Go](https://github.com/openset/leetcode/tree/master/problems/merge-two-binary-trees) | Easy |
 | <span id="616">616</span> | [Add Bold Tag in String](https://leetcode.com/problems/add-bold-tag-in-string) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/add-bold-tag-in-string) | Medium |
-| <span id="615">615</span> | [Average Salary: Departments VS Company](https://leetcode.com/problems/average-salary-departments-vs-company) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/average-salary-departments-vs-company) | Hard |
-| <span id="614">614</span> | [Second Degree Follower](https://leetcode.com/problems/second-degree-follower) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/second-degree-follower) | Medium |
-| <span id="613">613</span> | [Shortest Distance in a Line](https://leetcode.com/problems/shortest-distance-in-a-line) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/shortest-distance-in-a-line) | Easy |
-| <span id="612">612</span> | [Shortest Distance in a Plane](https://leetcode.com/problems/shortest-distance-in-a-plane) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/shortest-distance-in-a-plane) | Medium |
+| <span id="615">615</span> | [Average Salary: Departments VS Company](https://leetcode.com/problems/average-salary-departments-vs-company) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/average-salary-departments-vs-company) | Hard |
+| <span id="614">614</span> | [Second Degree Follower](https://leetcode.com/problems/second-degree-follower) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/second-degree-follower) | Medium |
+| <span id="613">613</span> | [Shortest Distance in a Line](https://leetcode.com/problems/shortest-distance-in-a-line) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/shortest-distance-in-a-line) | Easy |
+| <span id="612">612</span> | [Shortest Distance in a Plane](https://leetcode.com/problems/shortest-distance-in-a-plane) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/shortest-distance-in-a-plane) | Medium |
 | <span id="611">611</span> | [Valid Triangle Number](https://leetcode.com/problems/valid-triangle-number "有效三角形的个数") | [Go](https://github.com/openset/leetcode/tree/master/problems/valid-triangle-number) | Medium |
-| <span id="610">610</span> | [Triangle Judgement](https://leetcode.com/problems/triangle-judgement) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/triangle-judgement) | Easy |
+| <span id="610">610</span> | [Triangle Judgement](https://leetcode.com/problems/triangle-judgement) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/triangle-judgement) | Easy |
 | <span id="609">609</span> | [Find Duplicate File in System](https://leetcode.com/problems/find-duplicate-file-in-system "在系统中查找重复文件") | [Go](https://github.com/openset/leetcode/tree/master/problems/find-duplicate-file-in-system) | Medium |
-| <span id="608">608</span> | [Tree Node](https://leetcode.com/problems/tree-node) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/tree-node) | Medium |
-| <span id="607">607</span> | [Sales Person](https://leetcode.com/problems/sales-person) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/sales-person) | Easy |
+| <span id="608">608</span> | [Tree Node](https://leetcode.com/problems/tree-node) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/tree-node) | Medium |
+| <span id="607">607</span> | [Sales Person](https://leetcode.com/problems/sales-person) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/sales-person) | Easy |
 | <span id="606">606</span> | [Construct String from Binary Tree](https://leetcode.com/problems/construct-string-from-binary-tree "根据二叉树创建字符串") | [Go](https://github.com/openset/leetcode/tree/master/problems/construct-string-from-binary-tree) | Easy |
 | <span id="605">605</span> | [Can Place Flowers](https://leetcode.com/problems/can-place-flowers "种花问题") | [Go](https://github.com/openset/leetcode/tree/master/problems/can-place-flowers) | Easy |
 | <span id="604">604</span> | [Design Compressed String Iterator](https://leetcode.com/problems/design-compressed-string-iterator) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/design-compressed-string-iterator) | Easy |
-| <span id="603">603</span> | [Consecutive Available Seats](https://leetcode.com/problems/consecutive-available-seats) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/consecutive-available-seats) | Easy |
-| <span id="602">602</span> | [Friend Requests II: Who Has the Most Friends](https://leetcode.com/problems/friend-requests-ii-who-has-the-most-friends) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/friend-requests-ii-who-has-the-most-friends) | Medium |
+| <span id="603">603</span> | [Consecutive Available Seats](https://leetcode.com/problems/consecutive-available-seats) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/consecutive-available-seats) | Easy |
+| <span id="602">602</span> | [Friend Requests II: Who Has the Most Friends](https://leetcode.com/problems/friend-requests-ii-who-has-the-most-friends) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/friend-requests-ii-who-has-the-most-friends) | Medium |
 | <span id="601">601</span> | [Human Traffic of Stadium](https://leetcode.com/problems/human-traffic-of-stadium "体育馆的人流量") | [MySQL](https://github.com/openset/leetcode/tree/master/problems/human-traffic-of-stadium) | Hard |
 | <span id="600">600</span> | [Non-negative Integers without Consecutive Ones](https://leetcode.com/problems/non-negative-integers-without-consecutive-ones "不含连续1的非负整数") | [Go](https://github.com/openset/leetcode/tree/master/problems/non-negative-integers-without-consecutive-ones) | Hard |
 | <span id="599">599</span> | [Minimum Index Sum of Two Lists](https://leetcode.com/problems/minimum-index-sum-of-two-lists "两个列表的最小索引总和") | [Go](https://github.com/openset/leetcode/tree/master/problems/minimum-index-sum-of-two-lists) | Easy |
 | <span id="598">598</span> | [Range Addition II](https://leetcode.com/problems/range-addition-ii "范围求和 II") | [Go](https://github.com/openset/leetcode/tree/master/problems/range-addition-ii) | Easy |
-| <span id="597">597</span> | [Friend Requests I: Overall Acceptance Rate](https://leetcode.com/problems/friend-requests-i-overall-acceptance-rate) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/friend-requests-i-overall-acceptance-rate) | Easy |
+| <span id="597">597</span> | [Friend Requests I: Overall Acceptance Rate](https://leetcode.com/problems/friend-requests-i-overall-acceptance-rate) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/friend-requests-i-overall-acceptance-rate) | Easy |
 | <span id="596">596</span> | [Classes More Than 5 Students](https://leetcode.com/problems/classes-more-than-5-students "超过5名学生的课") | [MySQL](https://github.com/openset/leetcode/tree/master/problems/classes-more-than-5-students) | Easy |
 | <span id="595">595</span> | [Big Countries](https://leetcode.com/problems/big-countries "大的国家") | [MySQL](https://github.com/openset/leetcode/tree/master/problems/big-countries) | Easy |
 | <span id="594">594</span> | [Longest Harmonious Subsequence](https://leetcode.com/problems/longest-harmonious-subsequence "最长和谐子序列") | [Go](https://github.com/openset/leetcode/tree/master/problems/longest-harmonious-subsequence) | Easy |
@@ -451,24 +451,24 @@ LeetCode Problems' Solutions
 | <span id="589">589</span> | [N-ary Tree Preorder Traversal](https://leetcode.com/problems/n-ary-tree-preorder-traversal "N叉树的前序遍历") | [Go](https://github.com/openset/leetcode/tree/master/problems/n-ary-tree-preorder-traversal) | Easy |
 | <span id="588">588</span> | [Design In-Memory File System](https://leetcode.com/problems/design-in-memory-file-system) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/design-in-memory-file-system) | Hard |
 | <span id="587">587</span> | [Erect the Fence](https://leetcode.com/problems/erect-the-fence "安装栅栏") | [Go](https://github.com/openset/leetcode/tree/master/problems/erect-the-fence) | Hard |
-| <span id="586">586</span> | [Customer Placing the Largest Number of Orders](https://leetcode.com/problems/customer-placing-the-largest-number-of-orders) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/customer-placing-the-largest-number-of-orders) | Easy |
-| <span id="585">585</span> | [Investments in 2016](https://leetcode.com/problems/investments-in-2016) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/investments-in-2016) | Medium |
-| <span id="584">584</span> | [Find Customer Referee](https://leetcode.com/problems/find-customer-referee) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/find-customer-referee) | Easy |
+| <span id="586">586</span> | [Customer Placing the Largest Number of Orders](https://leetcode.com/problems/customer-placing-the-largest-number-of-orders) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/customer-placing-the-largest-number-of-orders) | Easy |
+| <span id="585">585</span> | [Investments in 2016](https://leetcode.com/problems/investments-in-2016) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/investments-in-2016) | Medium |
+| <span id="584">584</span> | [Find Customer Referee](https://leetcode.com/problems/find-customer-referee) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/find-customer-referee) | Easy |
 | <span id="583">583</span> | [Delete Operation for Two Strings](https://leetcode.com/problems/delete-operation-for-two-strings "两个字符串的删除操作") | [Go](https://github.com/openset/leetcode/tree/master/problems/delete-operation-for-two-strings) | Medium |
 | <span id="582">582</span> | [Kill Process](https://leetcode.com/problems/kill-process) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/kill-process) | Medium |
 | <span id="581">581</span> | [Shortest Unsorted Continuous Subarray](https://leetcode.com/problems/shortest-unsorted-continuous-subarray "最短无序连续子数组") | [Go](https://github.com/openset/leetcode/tree/master/problems/shortest-unsorted-continuous-subarray) | Easy |
-| <span id="580">580</span> | [Count Student Number in Departments](https://leetcode.com/problems/count-student-number-in-departments) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/count-student-number-in-departments) | Medium |
-| <span id="579">579</span> | [Find Cumulative Salary of an Employee](https://leetcode.com/problems/find-cumulative-salary-of-an-employee) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/find-cumulative-salary-of-an-employee) | Hard |
-| <span id="578">578</span> | [Get Highest Answer Rate Question](https://leetcode.com/problems/get-highest-answer-rate-question) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/get-highest-answer-rate-question) | Medium |
-| <span id="577">577</span> | [Employee Bonus](https://leetcode.com/problems/employee-bonus) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/employee-bonus) | Easy |
+| <span id="580">580</span> | [Count Student Number in Departments](https://leetcode.com/problems/count-student-number-in-departments) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/count-student-number-in-departments) | Medium |
+| <span id="579">579</span> | [Find Cumulative Salary of an Employee](https://leetcode.com/problems/find-cumulative-salary-of-an-employee) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/find-cumulative-salary-of-an-employee) | Hard |
+| <span id="578">578</span> | [Get Highest Answer Rate Question](https://leetcode.com/problems/get-highest-answer-rate-question) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/get-highest-answer-rate-question) | Medium |
+| <span id="577">577</span> | [Employee Bonus](https://leetcode.com/problems/employee-bonus) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/employee-bonus) | Easy |
 | <span id="576">576</span> | [Out of Boundary Paths](https://leetcode.com/problems/out-of-boundary-paths "出界的路径数") | [Go](https://github.com/openset/leetcode/tree/master/problems/out-of-boundary-paths) | Medium |
 | <span id="575">575</span> | [Distribute Candies](https://leetcode.com/problems/distribute-candies "分糖果") | [Go](https://github.com/openset/leetcode/tree/master/problems/distribute-candies) | Easy |
-| <span id="574">574</span> | [Winning Candidate](https://leetcode.com/problems/winning-candidate) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/winning-candidate) | Medium |
+| <span id="574">574</span> | [Winning Candidate](https://leetcode.com/problems/winning-candidate) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/winning-candidate) | Medium |
 | <span id="573">573</span> | [Squirrel Simulation](https://leetcode.com/problems/squirrel-simulation) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/squirrel-simulation) | Medium |
 | <span id="572">572</span> | [Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree "另一个树的子树") | [Go](https://github.com/openset/leetcode/tree/master/problems/subtree-of-another-tree) | Easy |
-| <span id="571">571</span> | [Find Median Given Frequency of Numbers](https://leetcode.com/problems/find-median-given-frequency-of-numbers) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/find-median-given-frequency-of-numbers) | Hard |
-| <span id="570">570</span> | [Managers with at Least 5 Direct Reports](https://leetcode.com/problems/managers-with-at-least-5-direct-reports) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/managers-with-at-least-5-direct-reports) | Medium |
-| <span id="569">569</span> | [Median Employee Salary](https://leetcode.com/problems/median-employee-salary) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/median-employee-salary) | Hard |
+| <span id="571">571</span> | [Find Median Given Frequency of Numbers](https://leetcode.com/problems/find-median-given-frequency-of-numbers) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/find-median-given-frequency-of-numbers) | Hard |
+| <span id="570">570</span> | [Managers with at Least 5 Direct Reports](https://leetcode.com/problems/managers-with-at-least-5-direct-reports) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/managers-with-at-least-5-direct-reports) | Medium |
+| <span id="569">569</span> | [Median Employee Salary](https://leetcode.com/problems/median-employee-salary) 🔒 | [MySQL](https://github.com/openset/leetcode/tree/master/problems/median-employee-salary) | Hard |
 | <span id="568">568</span> | [Maximum Vacation Days](https://leetcode.com/problems/maximum-vacation-days) 🔒 | [Go](https://github.com/openset/leetcode/tree/master/problems/maximum-vacation-days) | Hard |
 | <span id="567">567</span> | [Permutation in String](https://leetcode.com/problems/permutation-in-string "字符串的排列") | [Go](https://github.com/openset/leetcode/tree/master/problems/permutation-in-string) | Medium |
 | <span id="566">566</span> | [Reshape the Matrix](https://leetcode.com/problems/reshape-the-matrix "重塑矩阵") | [Go](https://github.com/openset/leetcode/tree/master/problems/reshape-the-matrix) | Easy |