coding-puzzle

My answers to LeetCode, HackerRank, Codewars etc.

Project Structure

coding-puzzle/
├── Java-training/
│   └── src/
│       ├── main/java/
│       │   ├── org/codewars/
│       │   │   ├── CloseCompare.java
│       │   │   └── ...
│       │   └── org/leetcode/
│       │       ├── TwoSum.java
│       │       └── ...
│       └── test/java/
│           ├── org/codewars/
│           │   ├── CloseCompareTest.java
│           │   └── ...
│           └── org/leetcode/
│               ├── TwoSumTest.java
│               └── ...
├── javascript-training/
│   ├── src/
│   │   ├── codewars/
│   │   │   ├── multiply.js
│   │   │   └── ...
│   │   └── leetcode/
│   │       ├── validPalindrome.js
│   │       └── ...
│   └── test/
│       ├── codewars/
│       │   ├── multiplyTest.js
│       │   └── ...
│       └── leetcode/
│           ├── validPalindromeTest.js
│           └── ...
├── typescript-training/
│   ├── src/
│   │   ├── codewars/
│   │   │   ├── rockPaperScissors.ts
│   │   │   └── ...
│   │   └── leetcode/
│   │       ├── twoSum.ts
│   │       └── ...
│   └── test/
│       ├── codewars/
│       │   ├── rockPaperScissorsTest.ts
│       │   └── ...
│       └── leetcode/
│           ├── twoSumTest.ts
│           └── ...
└── RandomWebSites/

Leetcode Problems

Leetcode Problems

No.	Questions	Language
1	Two Sum	Java
3	Longest Substring Without Repeating Characters	JavaScript
11	Container With Most Water	TypeScript
13	Roman To Integer	JavaScript
27	Remove Element	Java
34	Find First and Last Position of Element in Sorted Array	JavaScript
35	Search Insert Position	JavaScript
42	Trapping Rain Water	JavaScript
66	Plus One	Java
70	Climbing Stairs	TypeScript
75	Sort Colors	JavaScript
92	Rever Linked List II	JavaScript
125	Valid Palindrome	JavaScript
136	Single Number	Java
206	Reverse Linked List	Java
225	Implement Stack using Queues	JavaScript
232	Implement Queue using Stacks	JavaScript
268	Missing Number	JavaScript
287	Find the Duplicate Number	Java
387	First Unique Character in A String	JavaScript
412	Fizz Buzz	Java
680	Valid Palindrome II	JavaScript
704	Binary Search	JavaScript
844	Backspace String Compare	JavaScript
1351	Count Negative Numbers in a Sorted Matrix	JavaScript
2089	Find Target Indices After Sorting Array	JavaScript
2455	Average Value of Even Numbers That Are Divisible by Three	JavaScript
2485	Find the Pivot Integer	JavaScript
2529	Maximum Count of Positive Integer and Negative Integer	Java
2535	Difference Between Element Sum and Digit Sum of an Array	JavaScript
2536	Increment Submatrices by One	JavaScript

HackerRank Problems

HackerRank Problems

Questions	Language
Arrays - DS	JavaScript
2D Arrays - DS	JavaScript
HR Weather Observation Station 5	SQL
Java String Reverse	Java

Codewars Problems

Codewars Problems

Question	Language
Sum of positive	Java
Removing elements	Java
Convert a string to an array	Typescript
Is the string uppercase?	Java
Disemvowel Trolls	Java
My head is at the wrong end	Java
Opposite number	Java
Remove first and last character	Java
Rock Paper Scissors	Typescript
String ends with	Java
Sum Arrays	Java

Getting Started

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Prerequisites

JavaScript / TypeScript

• Node.js v18 or higher
• npm v9 or higher (bundled with Node.js)

Java

• JDK 17 or higher
• Gradle 8.14 or higher

Testing Stack

JavaScript / TypeScript

• Mocha — test runner (describe / it)
• Chai — assertion library (assert)
• ts-node — runs TypeScript test/source files directly without a separate build step (TypeScript repo only)

Java

• JUnit 5 — test framework (@Test, assertEquals)
• Gradle — build tool and test runner (./gradlew test)

Installation

JavaScript / TypeScript

npm install

Java — dependencies are resolved automatically the first time you run ./gradlew build or ./gradlew test; no separate install step needed.

Running Tests

JavaScript / TypeScript

npm test

This runs all test files matching test/**/*Test.ts (or .js, depending on the repo) via Mocha.

Java

Run all classes

./gradlew test

This runs all classes ending in Test under src/test/java via Gradle's built-in JUnit Platform support.

Run all tests

./gradlew test --tests "org.leetcode.ValidAnagramTest.*"

Run a specific test class

./gradlew test --tests "org.leetcode.ValidAnagramTest"

Run a single test method

./gradlew test --tests "org.leetcode.ValidAnagramTest.testCase2"

Run Tests using IntelliJ IDEA

1. Open JavaLeetCode and test folder

2. Click the 🟢 green play button:

   • Next to class → runs all tests
   • Next to method → runs a single test

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