VaibhavTalks

Your Engineering Journey Starts Here

Practice Problems & Patterns

Pattern-Based Mastery

Coding Practice & Algorithmic Patterns

Master the core algorithmic design patterns frequently evaluated in technical interviews at top engineering firms.

LeetCode

Industry-standard platform for practicing company-specific technical interview questions and contest rankings.

GeeksforGeeks

Extensive computer science repository with classic theoretical problems, company archives, and practice tracks.

CodeChef

Competitive programming platform with timed contests, division-rated challenges, and mathematical problem solving.

HackerRank

Domain-based skill certification challenges for data structures, algorithms, SQL, and core language proficiency.

High-Yield Problem Patterns

Focus on mastering the underlying invariant rather than memorizing individual solutions.

Open Online IDE

Array & Hashing

Beginner

Store observed elements in a Hash Table (unordered_map) to trade O(N) auxiliary space for O(1) instant frequency lookups.

Optimal Target: Time: O(N) | Space: O(N)
  • Two SumComplement Lookup via Hash Map
  • Contains DuplicateHash Set Membership Check
  • Valid AnagramCharacter Frequency Counting
  • Group AnagramsSorted String / Character Frequency Key
Test in Editor

Two Pointers

Intermediate

Operate two pointers converging from both ends or moving at different speeds across a sorted or sequential sequence in O(1) space.

Optimal Target: Time: O(N) | Space: O(1)
  • Valid PalindromeLeft & Right Converging Pointers
  • Two Sum II (Sorted)Shrinking Window on Sorted Array
  • 3SumFixed Pivot + Two Pointer Pair Search
  • Container With Most WaterGreedy Height Shrinking Strategy
Test in Editor

Sliding Window

Intermediate

Maintain a dynamic contiguous subarray window using left and right indices to avoid redundant nested re-computations.

Optimal Target: Time: O(N) | Space: O(K)
  • Best Time to Buy & Sell StockMinimum Price Tracking Window
  • Longest Substring Without RepeatsLast Seen Index Map with Sliding Left
  • Minimum Size Subarray SumDynamic Expansion & Contraction
  • Longest Repeating Character ReplacementMax Frequency in Dynamic Window
Test in Editor

Binary Search

Advanced

Repeatedly divide monotonic search spaces in half to locate boundaries or optimal target values in logarithmic time.

Optimal Target: Time: O(log N) | Space: O(1)
  • Standard Binary SearchClassic Monotonic Array Search
  • Search a 2D MatrixVirtual 1D Index Coordinate Mapping
  • Find Minimum in Rotated Sorted ArrayInflection Point Pivot Discovery
  • Koko Eating BananasBinary Search on Monotonic Answer Range
Test in Editor