tech-studies

LeetCode

2 min read

LeetCode

roadmap.sh: https://roadmap.sh/leetcode

Suggested path through the LeetCode nodes. Each node links to its lesson when written.

Nodes

Core Data Structures

  • Arrays
  • Strings
  • Hash Maps & Hash Sets
  • Linked Lists
  • Stacks
  • Queues & Deques
  • Trees (Binary Trees)
  • Binary Search Trees
  • Heaps / Priority Queues
  • Tries (Prefix Trees)
  • Graphs (adjacency list / matrix)
  • Union-Find (Disjoint Set)

Two Pointers

  • Opposite-Ends Two Pointers
  • Fast & Slow Pointers (cycle detection)
  • Sorting + Two Pointers (e.g. 3Sum)
  • Merging Sorted Inputs

Sliding Window

  • Fixed-Size Window
  • Variable-Size Window
  • Window with Hash Map (longest substring)
  • Window Maximum (monotonic deque)
  • Classic Binary Search
  • Search in Rotated Sorted Array
  • First / Last Occurrence (boundary search)
  • Binary Search on the Answer

Recursion & Backtracking

  • Recursion Fundamentals
  • Subsets & Combinations
  • Permutations
  • Backtracking with Pruning
  • N-Queens / Constraint Problems

Tree & Graph Traversal

  • DFS (recursive & iterative)
  • BFS (level-order)
  • Tree Path & Depth Problems
  • Topological Sort
  • Connected Components
  • Shortest Path (Dijkstra / BFS)
  • Cycle Detection in Graphs

Dynamic Programming

  • Memoization (top-down)
  • Tabulation (bottom-up)
  • 1D DP (climbing stairs, house robber)
  • 2D DP (grid paths, edit distance)
  • Knapsack Patterns
  • Longest Common / Increasing Subsequence
  • DP on Intervals & Strings

Greedy

  • Interval Scheduling
  • Greedy with Sorting
  • Greedy Exchange Argument & Proofs

Heaps & Priority Queues

  • Top-K Elements
  • Merge K Sorted Lists
  • Two-Heap (median of stream)

Tries

  • Building a Trie
  • Prefix Search & Autocomplete
  • Word Search / Dictionary Problems

Intervals

  • Merge Intervals
  • Insert Interval
  • Meeting Rooms

Bit Manipulation

  • Bitwise Operators
  • XOR Tricks (single number)
  • Bit Masking & Counting Bits

Math & Misc Patterns

  • Prefix Sums
  • Monotonic Stack
  • Cyclic Sort
  • Matrix Manipulation (rotate, spiral)

Practice Strategy

  • Big-O Time & Space Analysis
  • Pattern Recognition over Memorization
  • Spaced Repetition & Review Logs
  • Mock Interviews & Timed Sessions

Resources

See resources.md.

Project ideas

  • Build a personal pattern-tagged solutions repo where each solved problem is filed under its pattern (two pointers, DP, etc.) with a complexity note.
  • Implement every core data structure (heap, trie, union-find, deque) from scratch in your main language with unit tests.
  • Write a spaced-repetition tracker that resurfaces previously solved problems on a schedule so patterns stick.

1 item under this folder.