Algos by Example Cheat Sheet Blog

Algos by Example

A reference of algorithm patterns with annotated Go implementations. Each example is a runnable .go file.

Arrays & Hashing

Hash Map Lookup beginner O(n) / O(n)
Frequency Counting beginner O(n) / O(n)

Two Pointers

Pair Sum in Sorted Array beginner O(n) / O(1)
Converging Pointers intermediate O(n) / O(1)

Sliding Window

Variable-Size Window intermediate O(n) / O(min(n, m))

Binary Search

Search in Sorted Array beginner O(log n) / O(1)

Stacks

Balanced Brackets beginner O(n) / O(n)

Linked Lists

Reverse a Linked List beginner O(n) / O(1)

Trees

Tree Traversal intermediate O(n) / O(n)

Graphs

Grid Search (BFS/DFS) intermediate O(m * n) / O(m * n)

Dynamic Programming

Fibonacci / Linear DP intermediate O(n) / O(1)

Heaps

Top-K Elements intermediate O(n log k) / O(k)

Intervals

Merge Intervals intermediate O(n log n) / O(n)

Backtracking

Generate Subsets advanced O(2^n) / O(n)

Tries

Prefix Tree advanced O(m) / O(m * n)