Basecase is a structured DSA practice platform with curated sheets, pattern-based problem sets, streaks, and leaderboards — built for engineers who are serious about landing their dream role.
// Problem Library
Not just a list of problems. A library built around how patterns actually appear in interviews — so practicing one problem teaches you to solve ten.
Given an array of integers, return indices of two numbers that add up to a target.
Determine if an input string has valid open and close bracket pairs.
Merge two sorted linked lists into one sorted linked list.
Find the length of the longest substring without repeating characters.
Find all unique triplets in the array that sum to zero.
Compute how much water can be trapped after raining given elevation map.
// Curated Sheets
Every sheet is a complete learning track — ordered by concept, difficulty-ramped, and built around how interviews actually test you.
75 problems • 12,500 learners
→150 problems • 9,800 learners
→191 problems • 15,200 learners
→150 problems • 8,500 learners
→// Most Popular Tracks
Master the foundation. Two pointers, sliding window, prefix sums, and more.
From 1D to 2D DP. Memoization, tabulation, state machines explained.
BFS, DFS, Dijkstra, Union Find. Everything you need for graph mastery.
// AI Interview Practice
Our AI interviewer simulates real technical interviews — asking follow-ups, testing edge cases, and giving you instant feedback on your approach.
Adaptive questions based on your level
Real-time AI feedback on your solutions
Detailed post-interview analysis
Let's start with a classic. Given an array of integers, find two numbers such that they add up to a target. What's your approach?
I'd use a hash map to store values as I iterate. For each number, I check if the complement exists...
Good start! What's the time and space complexity? Can you handle duplicate values?
// Stay Consistent
Streaks, leaderboards, and badges aren't gimmicks — they're the difference between learning for a week and learning for a year.
day streak
3 / 11 badges earned
Every problem is tagged to a core pattern so you build transferable skills, not just solutions.
Sheets organized by topic, company track, and difficulty level — so you always know what to practice next.
Consistency beats intensity. Our streak system keeps you showing up even on the hard days.
See where you stand among thousands of learners. Compete, climb, and stay motivated.
Stuck? Get a nudge without spoiling the solution. Learn the thought process, not just the answer.
Submit your solution and get results in milliseconds. No waiting, no friction.
// AI-Powered Learning
Get personalized guidance, instant code reviews, and step-by-step explanations tailored to your learning style.
Join thousands of coders already using BaseCase to level up daily and land offers at top tech companies.