Complete Problem Index
Browse all 59 technical interview problems on our site. Each problem includes detailed strategy, complete solution with code, complexity analysis, and related problems.
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- Easy-Medium Problems (5)
- Medium Problems (49)
- Hard Problems (5)
Easy-Medium Problems (5)
Great for beginners and interview warm-ups. Most center on strings and linked lists, so use them to get fluent with the mechanics before a timed round. Several are palindrome and reversal questions that reduce to a clean two pointers walk from both ends — exactly the tidy solution interviewers hope you reach without hints.
- Check if a Linked list is a Palindrome or Not
- Find Longest Palindrome In A String
- Palindromes
- Reverse a doubly linked list
- Reverse a String
Medium Problems (49)
Most common interview difficulty. Master these for FAANG interviews. This is where the bulk of coding rounds live, and the skill being tested is recognizing which of the core coding patterns a problem maps to — a hash map for ‘Sum Up a Pair in Array’, a topological sort for dependency ordering, or a design-flavored question like ‘Implement a rate limiter’ that pulls in system design. Interviewers probe whether you can name the time and space cost of your approach before you write code, then tighten it when pushed.
- 100 Factorial
- Amazon Interview Question: Count Negative Integers in Matrix
- Bit Manipulation: Essential Tricks and Techniques
- Boolean String Value
- Box ‘o Numbers
- Building a Stack with a getMax() function
- Bumblebee
- Card Trick Without the Trick
- Check If a Number is Power of Two
- Chessboard
- Classic Weighing
- Clock
- Coin Rolls
- Compute X^Y For Floats and Negative Values
- Cube
- Find Out if a Linked List has a Cycle
- Find The Depth of a Binary Tree
- Fruit Jar Problem
- Function that Multiples 2 Integers
- Fuse on Fire
- Getting a fair result with an unfair coin
- Gold Chain
- How many floors can an egg be dropped without breaking?
- Implement a Function to Return a Ratio
- Implement a rate limiter
- Implement LRU Cache
- Implement Trie (Prefix Tree)
- int atoi( char* pStr )
- Kadane’s Algorithm: Maximum Subarray Sum
- Linked List
- Missing country code
- Missing or Duplicate Number in an Array
- Monty Hall Problem
- Prime number problem
- Print String Permutations
- Probability Distribution Function
- Red Marbles, Blue Marbles
- Removing a Character from a String
- Right Rotate an array by k elements
- Server to Process Fair Number of Functions
- Sliding Window Maximum
- Storing 1 million phone numbers
- Sum it Up
- Sum Up a Pair in Array
- Topological Sort
- Treasure Island
- Write a Function for r and 5()
- Write a program for producer-consumer problem
- XOR using NAND gates
Hard Problems (5)
Advanced problems for senior roles and top companies. Expect graph and structure-heavy algorithms — Dijkstra’s shortest path, union-find for connected components, and serializing a binary tree — where the interviewer weighs your data-structure choice and edge-case handling as much as a working answer. A concrete tell of a strong candidate: name the complexity, cover the empty and single-node cases, and explain why the chosen structure beats the naive one.
