LeetCode in TypeScript: Table of Content

These problems test fundamental concepts that are critical for interviews at companies like Google, Meta, Amazon, Apple, and Microsoft. They can be solved in any language, including TypeScript, and focus on algorithmic thinking.

1. Two Sum (Easy)

   • Problem: Given an array of integers, return indices of the two numbers such that they add up to a specific target.
   • Why It’s Relevant: This is one of the most common interview problems to test array manipulation and hash maps. It’s often used as a warm-up question at companies like Amazon and Google.
   • Key Concepts: Arrays, Hash Maps, Time Complexity (O(n)).

2. Reverse Linked List (Easy)

   • Problem: Reverse a singly linked list.
   • Why It’s Relevant: Linked lists are a fundamental data structure, and reversing one tests pointer manipulation skills. Frequently asked at Meta and Microsoft.
   • Key Concepts: Linked Lists, Iteration vs. Recursion.

3. Valid Parentheses (Easy)

   • Problem: Given a string containing just the characters ’(’, ’)’, ’{’, ’}’, ’[’ and ’]’, determine if the input string is valid.
   • Why It’s Relevant: Tests stack usage and string parsing, a common topic for entry-level questions at companies like Apple.
   • Key Concepts: Stacks, String Manipulation.

4. Merge Two Sorted Lists (Easy)

   • Problem: Merge two sorted linked lists and return it as a sorted list.
   • Why It’s Relevant: Tests linked list traversal and merging logic, often seen in Amazon interviews.
   • Key Concepts: Linked Lists, Pointers.

5. Best Time to Buy and Sell Stock (Easy/Medium)

   • Problem: Given an array of stock prices, find the maximum profit by buying on one day and selling on a later day.
   • Why It’s Relevant: Tests array traversal and greedy algorithms, a popular topic at Google and hedge fund tech roles.
   • Key Concepts: Arrays, Greedy Algorithms.

6. Longest Substring Without Repeating Characters (Medium)

   • Problem: Given a string, find the length of the longest substring without repeating characters.
   • Why It’s Relevant: Tests sliding window technique and hash maps, a favorite at Meta and Google for medium-difficulty questions.
   • Key Concepts: Strings, Sliding Window, Hash Maps.

7. Merge Intervals (Medium)

   • Problem: Given an array of intervals, merge all overlapping intervals.
   • Why It’s Relevant: Tests sorting and interval logic, often asked in Amazon and Microsoft interviews to assess handling of real-world data problems.
   • Key Concepts: Arrays, Sorting, Intervals.

8. Word Break (Medium)

   • Problem: Given a string and a dictionary of words, determine if the string can be segmented into a space-separated sequence of dictionary words.
   • Why It’s Relevant: Tests dynamic programming, a critical topic for interviews at Google and Meta.
   • Key Concepts: Dynamic Programming, Strings.

9. LRU Cache (Medium/Hard)

   • Problem: Design and implement a Least Recently Used (LRU) cache.
   • Why It’s Relevant: Tests design skills and understanding of hash maps and doubly linked lists, often asked in system design-adjacent coding rounds at Amazon and Google.
   • Key Concepts: Hash Maps, Doubly Linked Lists, Design.

10. Median of Two Sorted Arrays (Hard)

    • Problem: Given two sorted arrays, find the median of the two sorted arrays.
    • Why It’s Relevant: Tests binary search and edge-case handling, a challenging problem often used in final rounds at top-tier companies like Google.
    • Key Concepts: Binary Search, Arrays, Edge Cases.