{"id":50643382,"url":"https://github.com/ngkhang/leetcode-old","last_synced_at":"2026-06-07T10:31:09.661Z","repository":{"id":313217695,"uuid":"1042139321","full_name":"ngkhang/leetcode-old","owner":"ngkhang","description":"My collection of solutions to algorithmic problems in Leetcode","archived":false,"fork":false,"pushed_at":"2025-11-17T07:10:41.000Z","size":284,"stargazers_count":1,"open_issues_count":0,"forks_count":0,"subscribers_count":0,"default_branch":"main","last_synced_at":"2026-02-21T20:56:47.644Z","etag":null,"topics":["data-structures-and-algorithms","database","dsa","javascript","leetcode","mysql","typescript"],"latest_commit_sha":null,"homepage":"","language":"JavaScript","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/ngkhang.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null,"notice":null,"maintainers":null,"copyright":null,"agents":null,"dco":null,"cla":null}},"created_at":"2025-08-21T14:42:12.000Z","updated_at":"2026-02-21T05:57:49.000Z","dependencies_parsed_at":"2025-09-04T16:55:51.223Z","dependency_job_id":"ffaf434d-cff4-44ea-9ef7-e01ae5800b34","html_url":"https://github.com/ngkhang/leetcode-old","commit_stats":null,"previous_names":["ngkhang/leetcode"],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/ngkhang/leetcode-old","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ngkhang%2Fleetcode-old","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ngkhang%2Fleetcode-old/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ngkhang%2Fleetcode-old/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ngkhang%2Fleetcode-old/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/ngkhang","download_url":"https://codeload.github.com/ngkhang/leetcode-old/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/ngkhang%2Fleetcode-old/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":34018404,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-05-26T15:22:16.424Z","status":"online","status_checked_at":"2026-06-07T02:00:07.652Z","response_time":124,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["data-structures-and-algorithms","database","dsa","javascript","leetcode","mysql","typescript"],"created_at":"2026-06-07T10:31:06.536Z","updated_at":"2026-06-07T10:31:09.653Z","avatar_url":"https://github.com/ngkhang.png","language":"JavaScript","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Leetcode\n\n\u003cdiv style=\"text-align: center\"\u003e\n \u003cimg style=\"width: 100%\" src=\"./leetcode-logo.png\" alt=\"logo LeetCode\"/\u003e\n\u003c/div\u003e\n\n\u003e This repo is a collection of solutions to problems in LeetCode.\n\n- This is [my profile in LeetCode](https://leetcode.com/ngkhang/), I will upload solutions for some problems regularly.\n\n## Table of Contents\n\n- [Leetcode](#leetcode)\n - [Table of Contents](#table-of-contents)\n - [Solutions](#solutions)\n - [JavaScript and TypeScript](#javascript-and-typescript)\n - [Database](#database)\n - [References](#references)\n\n---\n\n## Solutions\n\n### JavaScript and TypeScript\n\n| Problems | Difficulty | Solutions |\n| ----------------------------------------------------------------------------------------------------------------------------------------------- | ---------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| [1. Two Sum](https://leetcode.com/problems/two-sum/) | ⭐ | [JS](./solutions/javascript/1-two-sum.js) - [TS](./solutions/typescript/1-two-sum.ts) |\n| [13. Roman To Integer](https://leetcode.com/problems/roman-to-integer/) | ⭐ | [JS](./solutions/javascript/13-roman-to-integer.js) - [TS](./solutions/typescript/13-roman-to-integer.ts) |\n| [14. Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix/) | ⭐ | [JS](./solutions/javascript/14-longest-common-prefix.js) - [TS](./solutions/typescript/14-longest-common-prefix.ts) |\n| [26. Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/) | ⭐ | [JS](./solutions/javascript/26-remove-duplicates-from-sorted-array.js) - [TS](./solutions/typescript/26-remove-duplicates-from-sorted-array.ts) |\n| [28. Find the Index of the First Occurrence in a String](https://leetcode.com/problems/find-the-index-of-the-first-occurrence-in-a-string/) | ⭐ | [JS](./solutions/javascript/28-find-the-index-of-the-first-occurrence-in-a-string.js) - [TS](./solutions/typescript/28-find-the-index-of-the-first-occurrence-in-a-string.ts) |\n| [35. Search Insert Position](https://leetcode.com/problems/search-insert-position/) | ⭐ | [JS](./solutions/javascript/35-search-insert-position.js) - [TS](./solutions/typescript/35-search-insert-position.ts) |\n| [58. Length of Last Word](https://leetcode.com/problems/length-of-last-word/) | ⭐ | [JS](./solutions/javascript/58-length-of-last-word.js) - [TS](./solutions/typescript/58-length-of-last-word.ts) |\n| [66. Plus One](https://leetcode.com/problems/plus-one/) | ⭐ | [JS](./solutions/javascript/66-plus-one.js) - [TS](./solutions/typescript/66-plus-one.ts) |\n| [67. Add Binary](https://leetcode.com/problems/add-binary/) | ⭐ | [JS](./solutions/javascript/67-add-binary.js) - [TS](./solutions/typescript/67-add-binary.ts) |\n| [75. Sort Colors](https://leetcode.com/problems/sort-colors/) | ⭐ | [JS](./solutions/javascript/75-sort-colors.js) - [TS](./solutions/typescript/75-sort-colors.ts) |\n| [83. Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/) | ⭐ | [JS](./solutions/javascript/83-remove-duplicates-from-sorted-list.js) - [TS](./solutions/typescript/83-remove-duplicates-from-sorted-list.ts) |\n| [88. Merge Sorted Array](https://leetcode.com/problems/merge-sorted-array/) | ⭐ | [JS](./solutions/javascript/88-merge-sorted-array.js) - [TS](./solutions/typescript/88-merge-sorted-array.ts) |\n| [125. Valid Palindrome](https://leetcode.com/problems/valid-palindrome/) | ⭐ | [JS](./solutions/javascript/125-valid-palindrome.js) - [TS](./solutions/typescript/125-valid-palindrome.ts) |\n| [136. Single Number](https://leetcode.com/problems/single-number/) | ⭐ | [JS](./solutions/javascript/136-single-number.js) - [TS](./solutions/typescript/136-single-number.ts) |\n| [137. Single Number II](https://leetcode.com/problems/single-number-ii/) | ⭐⭐ | [JS](./solutions/javascript/137-single-number-ii.js) - [TS](./solutions/typescript/137-single-number-ii.ts) |\n| [217. Contains Duplicate](https://leetcode.com/problems/contains-duplicate/) | ⭐ | [JS](./solutions/javascript/217-contains-duplicate.js) - [TS](./solutions/typescript/217-contains-duplicate.ts) |\n| [219. Contains Duplicate II](https://leetcode.com/problems/contains-duplicate-ii/) | ⭐ | [JS](./solutions/javascript/219-contains-duplicate-ii.js) - [TS](./solutions/typescript/219-contains-duplicate-ii.ts) |\n| [242. Valid Anagram](https://leetcode.com/problems/valid-anagram/) | ⭐ | [JS](./solutions/javascript/242-valid-anagram.js) - [TS](./solutions/typescript/242-valid-anagram.ts) |\n| [260. Single Number III](https://leetcode.com/problems/single-number-iii/) | ⭐⭐ | [JS](./solutions/javascript/260-single-number-iii.js) - [TS](./solutions/typescript/260-single-number-iii.ts) |\n| [268. Missing Number](https://leetcode.com/problems/missing-number/) | ⭐ | [JS](./solutions/javascript/268-missing-number.js) - [TS](./solutions/typescript/268-missing-number.ts) |\n| [349. Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/) | ⭐ | [JS](./solutions/javascript/349-intersection-of-two-array.js) - [TS](./solutions/typescript/349-intersection-of-two-array.ts) |\n| [350. Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/) | ⭐ | [JS](./solutions/javascript/350-intersection-of-two-arrays-ii.js) - [TS](./solutions/typescript/350-intersection-of-two-arrays-ii.ts) |\n| [367. Valid Perfect Square](https://leetcode.com/problems/valid-perfect-square/) | ⭐ | [JS](./solutions/javascript/367-valid-perfect-square.js) - [TS](./solutions/typescript/367-valid-perfect-square.ts) |\n| [383. Ransom Note](https://leetcode.com/problems/ransom-note/) | ⭐ | [JS](./solutions/javascript/383-ransom-note.js) - [TS](./solutions/typescript/383-ransom-note.ts) |\n| [387. First Unique Character in a String](https://leetcode.com/problems/first-unique-character-in-a-string/) | ⭐ | [JS](./solutions/javascript/387-first-unique-character-in-a-string.js) - [TS](./solutions/typescript/387-first-unique-character-in-a-string.ts) |\n| [389. Find The Difference](https://leetcode.com/problems/find-the-difference/) | ⭐ | [JS](./solutions/javascript/389-find-the-difference.js) - [TS](./solutions/typescript/389-find-the-difference.ts) |\n| [415. Add Strings](https://leetcode.com/problems/add-strings/) | ⭐ | [JS](./solutions/javascript/415-add-strings.js) - [TS](./solutions/typescript/415-add-strings.ts) |\n| [448. Find All Numbers Disappeared in an Array](https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/) | ⭐ | [JS](./solutions/javascript/448-find-all-numbers-disappeared-in-an-array.js) - [TS](./solutions/typescript/448-find-all-numbers-disappeared-in-an-array.ts) |\n| [485. Max Consecutive Ones](https://leetcode.com/problems/max-consecutive-ones/) | ⭐ | [JS](./solutions/javascript/485-max-consecutive-ones.js) - [TS](./solutions/typescript/485-max-consecutive-ones.ts) |\n| [500. Keyboard Row](https://leetcode.com/problems/keyboard-row/) | ⭐ | [JS](./solutions/javascript/500-keyboard-row.js) - [TS](./solutions/typescript/500-keyboard-row.ts) |\n| [717. 1-bit and 2-bit Characters](https://leetcode.com/problems/1-bit-and-2-bit-characters/) | ⭐ | [JS](./solutions/javascript/717-1-bit-and-2-bit-characters.js) - [TS](./solutions/typescript/717-1-bit-and-2-bit-characters.ts) |\n| [884. Uncommon Words from Two Sentences](https://leetcode.com/problems/uncommon-words-from-two-sentences/) | ⭐ | [JS](./solutions/javascript/884-uncommon-words-from-two-sentences.js) - [TS](./solutions/typescript/884-uncommon-words-from-two-sentences.ts) |\n| [989. Add To Array Form Of Integer](https://leetcode.com/problems/add-to-array-form-of-integer/) | ⭐ | [JS](./solutions/javascript/989-add-to-array-form-of-integer.js) - [TS](./solutions/typescript/989-add-to-array-form-of-integer.ts) |\n| [1103. Distribute Candies to People](https://leetcode.com/problems/distribute-candies-to-people/) | ⭐ | [JS](./solutions/javascript/1103-distribute-candies-to-people.js) - [TS](./solutions/typescript/1103-distribute-candies-to-people.ts) |\n| [1160. Find Words That Can Be Formed by Characters](https://leetcode.com/problems/find-words-that-can-be-formed-by-characters/) | ⭐ | [JS](./solutions/javascript/1160-find-words-that-can-be-formed-by-characters.js) - [TS](./solutions/typescript/1160-find-words-that-can-be-formed-by-characters.ts) |\n| [1323. Maximum 69 Number](https://leetcode.com/problems/maximum-69-number/) | ⭐ | [JS](./solutions/javascript/1323-maximum-69-number.js) - [TS](./solutions/typescript/1323-maximum-69-number.ts) |\n| [1342. Number of Steps to Reduce a Number to Zero](https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/) | ⭐ | [JS](./solutions/javascript/1342-number-of-steps-to-reduce-a-number-to-zero.js) - [TS](./solutions/typescript/1342-number-of-steps-to-reduce-a-number-to-zero.ts) |\n| [1437. Check If All 1's Are at Least Length K Places Away](https://leetcode.com/problems/check-if-all-1s-are-at-least-length-k-places-away/) | ⭐ | [JS](./solutions/javascript/1437-check-if-all-1s-are-at-least-length-k-places-away.js) - [TS](./solutions/typescript/1437-check-if-all-1s-are-at-least-length-k-places-away.ts) |\n| [1470. Shuffle the Array](https://leetcode.com/problems/shuffle-the-array/) | ⭐ | [JS](./solutions/javascript/1470-shuffle-the-array.js) - [TS](./solutions/typescript/1470-shuffle-the-array.ts) |\n| [1716. Calculate Money in Leetcode Bank](https://leetcode.com/problems/calculate-money-in-leetcode-bank/) | ⭐ | [JS](./solutions/javascript/1716-calculate-money-in-leetcode-bank.js) - [TS](./solutions/typescript/1716-calculate-money-in-leetcode-bank.ts) |\n| [1768. Merge Strings Alternately](https://leetcode.com/problems/merge-strings-alternately/) | ⭐ | [JS](./solutions/javascript/1768-merge-strings-alternately.js) - [TS](./solutions/typescript/1768-merge-strings-alternately.ts) |\n| [1929. Concatenation Of Array](https://leetcode.com/problems/concatenation-of-array/) | ⭐ | [JS](./solutions/javascript/1929-concatenation-of-array.js) - [TS](./solutions/typescript/1929-concatenation-of-array.ts) |\n| [1980. Find Unique Binary String](https://leetcode.com/problems/find-unique-binary-string/) | ⭐ | [JS](./solutions/javascript/1980-find-unique-binary-string.js) - [TS](./solutions/typescript/1980-find-unique-binary-string.ts) |\n| [2011. Final Value of Variable After Performing Operations](https://leetcode.com/problems/final-value-of-variable-after-performing-operations/) | ⭐ | [JS](./solutions/javascript/2011-final-value-of-variable-after-performing-operations.js) - [TS](./solutions/typescript/2011-final-value-of-variable-after-performing-operations.ts) |\n| [2053. Kth Distinct String In An Array](https://leetcode.com/problems/kth-distinct-string-in-an-array/) | ⭐ | [JS](./solutions/javascript/2053-kth-distinct-string-in-an-array.js) - [TS](./solutions/typescript/2053-kth-distinct-string-in-an-array.ts) |\n| [2139. Minimum Moves to Reach Target Score](https://leetcode.com/problems/minimum-moves-to-reach-target-score/) | ⭐⭐ | [JS](./solutions/javascript/2139-minimum-moves-to-reach-target-score.js) - [TS](./solutions/typescript/2139-minimum-moves-to-reach-target-score.ts) |\n| [2169. Count Operations To Obtain Zero](https://leetcode.com/problems/count-operations-to-obtain-zero/) | ⭐ | [JS](./solutions/javascript/2169-count-operations-to-obtain-zero.js) - [TS](./solutions/typescript/2169-count-operations-to-obtain-zero.ts) |\n| [2215. Find The Difference Of Two Arrays](https://leetcode.com/problems/find-the-difference-of-two-arrays/) | ⭐ | [JS](./solutions/javascript/2215-find-the-difference-of-two-arrays.js) - [TS](./solutions/typescript/2215-find-the-difference-of-two-arrays.ts) |\n| [2248. Intersection Of Multiple Arrays](https://leetcode.com/problems/intersection-of-multiple-arrays/) | ⭐ | [JS](./solutions/javascript/2248-intersection-of-multiple-arrays.js) - [TS](./solutions/typescript/2248-intersection-of-multiple-arrays.ts) |\n| [2351. First Letter To Appear Twice](https://leetcode.com/problems/first-letter-to-appear-twice/) | ⭐ | [JS](./solutions/javascript/2351-first-letter-to-appear-twice.js) - [TS](./solutions/typescript/2351-first-letter-to-appear-twice.ts) |\n| [2399. Check Distances Between Same Letters](https://leetcode.com/problems/check-distances-between-same-letters/) | ⭐ | [JS](./solutions/javascript/2399-check-distances-between-same-letters.js) - [TS](./solutions/typescript/2399-check-distances-between-same-letters.ts) |\n| [2432. The Employee That Worked on the Longest Task](https://leetcode.com/problems/the-employee-that-worked-on-the-longest-task/) | ⭐ | [JS](./solutions/javascript/2432-the-employee-that-worked-on-the-longest-task.js) - [TS](./solutions/typescript/2432-the-employee-that-worked-on-the-longest-task.ts) |\n| [2460. Apply Operations to an Array](https://leetcode.com/problems/apply-operations-to-an-array/) | ⭐ | [JS](./solutions/javascript/2460-apply-operations-to-an-array.js) - [TS](./solutions/typescript/2460-apply-operations-to-an-array.ts) |\n| [3065. Minimum Operations to Exceed Threshold Value I](https://leetcode.com/problems/minimum-operations-to-exceed-threshold-value-i/) | ⭐ | [JS](./solutions/javascript/3065-minimum-operations-to-exceed-threshold-value-i.js) - [TS](./solutions/typescript/3065-minimum-operations-to-exceed-threshold-value-i.ts) |\n| [3289. The Two Sneaky Numbers of Digitville](https://leetcode.com/problems/the-two-sneaky-numbers-of-digitville/) | ⭐ | [JS](./solutions/javascript/3289-the-two-sneaky-numbers-of-digitville.js) - [TS](./solutions/typescript/3289-the-two-sneaky-numbers-of-digitville.ts) |\n\n### Database\n\n| Problems | Difficulty | Solutions |\n| --------------------------------------------------------------------------------------------------------------------------------------------------- | ---------- | ---------------------------------------------------------------------------------------- |\n| [181. Employees Earning More Than Their Managers](https://leetcode.com/problems/employees-earning-more-than-their-managers/) | ⭐ | [📝](./solutions/database/181-employees-earning-more-than-their-managers.sql) |\n| [182. Duplicate Emails](https://leetcode.com/problems/duplicate-emails/) | ⭐ | [📝](./solutions/database/182-duplicate-emails.sql) |\n| [183. Customers Who Never Order](https://leetcode.com/problems/customers-who-never-order/) | ⭐ | [📝](./solutions/database/183-customers-who-never-order.sql) |\n| [196. Delete Duplicate Emails](https://leetcode.com/problems/delete-duplicate-emails/) | ⭐ | [📝](./solutions/database/196-delete-duplicate-emails.sql) |\n| [197. Rising Temperature](https://leetcode.com/problems/rising-temperature/) | ⭐ | [📝](./solutions/database/197-rising-temperature.sql) |\n| [511. Game Play Analysis I](https://leetcode.com/problems/game-play-analysis-i/) | ⭐ | [📝](./solutions/database/511-game-play-analysis-i.sql) |\n| [577. Employee Bonus](https://leetcode.com/problems/employee-bonus/) | ⭐ | [📝](./solutions/database/577-employee-bonus.sql) |\n| [584. Find Customer Referee](https://leetcode.com/problems/find-customer-referee/) | ⭐ | [📝](./solutions/database/584-find-customer-referee.sql) |\n| [586. Customer Placing the Largest Number of Orders](https://leetcode.com/problems/customer-placing-the-largest-number-of-orders/) | ⭐ | [📝](./solutions/database/586-customer-placing-the-largest-number-of-orders.sql) |\n| [595. Big Countries](https://leetcode.com/problems/big-countries/) | ⭐ | [📝](./solutions/database/595-big-countries.sql) |\n| [596. Classes More Than 5 Students](https://leetcode.com/problems/classes-with-at-least-5-students/) | ⭐ | [📝](./solutions/database/596-classes-with-at-least-5-students.sql) |\n| [610. Triangle Judgement](https://leetcode.com/problems/triangle-judgement/) | ⭐ | [📝](./solutions/database/610-triangle-judgement.sql) |\n| [620. Not Boring Movies](https://leetcode.com/problems/not-boring-movies/) | ⭐ | [📝](./solutions/database/620-not-boring-movies.sql) |\n| [627. Swap Salary](https://leetcode.com/problems/swap-salary/) | ⭐ | [📝](./solutions/database/627-swap-salary.sql) |\n| [1068. Product Sales Analysis I](https://leetcode.com/problems/product-sales-analysis-i/) | ⭐ | [📝](./solutions/database/1068-product-sales-analysis-i.sql) |\n| [1075. Project Employees I](https://leetcode.com/problems/project-employees-i) | ⭐ | [📝](./solutions/database/1075-project-employees-i.sql) |\n| [1148. Article Views I](https://leetcode.com/problems/article-views-i/) | ⭐ | [📝](./solutions/database/1148-article-views-i.sql) |\n| [1683. Invalid Tweets](https://leetcode.com/problems/invalid-tweets/) | ⭐ | [📝](./solutions/database/1683-invalid-tweets.sql) |\n| [1731. The Number of Employees Which Report to Each Employee](https://leetcode.com/problems/the-number-of-employees-which-report-to-each-employee/) | ⭐ | [📝](./solutions/database/1731-the-number-of-employees-which-report-to-each-employee.sql) |\n| [1741. Find Total Time Spent by Each Employee](https://leetcode.com/problems/find-total-time-spent-by-each-employee/) | ⭐ | [📝](./solutions/database/1741-find-total-time-spent-by-each-employee.sql) |\n| [1757. Recyclable and Low Fat Products](https://leetcode.com/problems/recyclable-and-low-fat-products/) | ⭐ | [📝](./solutions/database/1757-recyclable-and-low-fat-products.sql) |\n| [3436. Find Valid Emails](https://leetcode.com/problems/find-valid-emails/) | ⭐ | [📝](./solutions/database/3436-find-valid-emails.sql) |\n\n---\n\n## References\n\n- [🔗 Big-O cheat sheet](https://www.bigocheatsheet.com/)\n- Visualizations\n - [🔗 Visualgo](https://visualgo.net/en)\n - [🔗 Data Structure Visualizations](https://www.cs.usfca.edu/~galles/visualization/Algorithms.html)\n\n[⬆️ Scroll top](#leetcode)\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fngkhang%2Fleetcode-old","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fngkhang%2Fleetcode-old","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fngkhang%2Fleetcode-old/lists"}