Revquix 300

Revquix 300 is a curated list of 300 DSA problems that cover every core topic, from arrays to dynamic programming, in five languages.

It is complete interview preparation: the 150 problems plus 150 more, covering every core topic in depth, from easy warm-ups to hard challenges. Every problem is judged against hidden test cases in Python, C++, Java, JavaScript and TypeScript, and each section runs from easy to hard. Revquix 300 includes every problem in Revquix 150, and Revquix 150 includes every problem in Revquix 80.

What you will practise:

• Arrays, Strings and Hashing: 40 problems such as How Many Times, Over a Third and XOR Path Meet.
• Two Pointers and Sliding Window: 24 problems such as Sorted Squares, Two Squares Make It and Palindrome by Swaps.
• Sorting, Binary Search and Intervals: 32 problems such as Top Two Product, First and Last Seen and Weighted Equaliser.
• Linked Lists: 20 problems such as Turn the Chain Around, Ends Inward and Express Lanes List.
• Stacks and Queues: 22 problems such as Bracket Balance, Rock Collisions and Layered Increments.
• Trees and Binary Search Trees: 38 problems such as Tree Depth, Floor Maximums and Merge Small Search Trees.
• Heaps and Greedy: 20 problems such as Flowerbed Planner, Cooldown Scheduler and Kth Cheapest Row Picks.
• Recursion and Backtracking: 18 problems such as Power of Three Climb, Reusable Coins to Target and Tug of War.
• Graphs: 32 problems such as Paint Bucket, Course Plan Feasible and Second-Best Network.
• Dynamic Programming: 44 problems such as Triangle of Sums, Two Equal Piles and Twin Billboards.
• Tries, Bit Manipulation and Design: 10 problems such as The Lone Sock, Prefix Tree and Find All Words.

Work through one section at a time and finish a section before you move on. If a problem feels too hard, try an easier one from the same section first, then come back to it. Every problem comes with worked examples and clear constraints.