π§ Algorithm Problems Solutions A collection of solved algorithm problems from LeetCode , NeetCode , FreeCodeCamp , and HackerRank .
Platform
Problems Solved
LeetCode
71
NeetCode
6
FreeCodeCamp
13
HackerRank
4
| Problem | Solution | Category |
|---------|----------|----------|| Binary Search | JavaScript | Binary Search || Contains Duplicate | JavaScript | Arrays & Hashing |
| Is Palindrome | JavaScript | Two Pointers |
| Reverse Linked List | JavaScript | Linked Lists |
| Top K Frequent Elements | JavaScript | Arrays & Hashing |
| Valid Anagram | JavaScript | Arrays & Hashing |
π₯ FreeCodeCamp Problems
Problem
Solution
Description
Array Swap
JavaScript Reverse an array
FizzBuzz Mini
JavaScript Return Fizz, Buzz, FizzBuzz, or the number
Flatten the Array
JavaScript Flatten a nested array
Good day
JavaScript Return greeting based on time of day
Is Flat
JavaScript Check if an array has no nested arrays
Is Odd or Even
JavaScript Check if a number is odd or even
Is Valid Hex
JavaScript Validate hex color codes
Letter and Number Count
JavaScript Count letters and numbers in a string
Odd or Even Day
JavaScript Check if a day of month is odd or even
Parsec Converter
JavaScript Convert parsec values based on odd/even
Rock Paper Scissors
JavaScript Classic RPS game implementation
Sorted Array
JavaScript Array sorting algorithm
Truncate Text
JavaScript Truncate text to 20 chars with ellipsis
Algorithm
Solution
Time Complexity
Space Complexity
Bubble Sort
Python O(nΒ²)
O(1)
Merge Sort
Python O(n log n)
O(n)
Quick Sort
Python O(n log n)
O(log n)
Algorithm
Solution
Time Complexity
Space Complexity
Dijkstra
Python O((V + E) log V)
O(V)
Structure
Solution
Description
Binary Tree
Python Basic binary tree implementation
Hashmap
Python Hash map implementation with put, get, and remove operations
Min Heap
Python Min heap implementation
Stack
Python Linked-list stack with push, pop, peek, and size operations
Trie
Python , Nim Prefix tree with insert, search, and starts_with operations
JavaScript - Primary language for most solutionsTypeScript - Type-safe JavaScript solutionsPython - Clean and readable solutionsScala - Functional programming approachJava - Object-oriented solutionsNim - Fast and expressive systems programming language
π File Naming Convention
LeetCode: {problem-number}-{problem-name}.{extension}
NeetCode: neetcode-{problem-name}.{extension}
FreeCodeCamp: freecodecamp-{problem-name}.{extension}
HackerRank: hackerhank-{problem-name}.{extension}
node filename.js
# or with ts-node for TypeScript javac filename.java && java ClassName This repository is for educational purposes. Feel free to use the solutions as reference for learning.
β Happy Coding!
