Why Data Structures Matter

Choosing the right data structure is often the single biggest lever for algorithm performance. This quick guide distils the most commonly used structures into a single visual reference.

Core Structures at a Glance

  • Arrays — cache-friendly sequential access, O(1) index lookup, O(n) insert/delete
  • Linked Lists — O(1) insertions at arbitrary positions, O(n) lookup
  • Hash Maps — O(1) average-case lookups and inserts
  • Binary Search Trees — O(log n) ordered data operations
  • Heaps — O(1) max/min access, O(log n) insert — perfect for priority queues
  • Graphs — model relationships, traversed with BFS/DFS

TypeScript Quick Implementation

// Min-Heap in TypeScript
class MinHeap {
  private heap: number[] = [];
  push(val: number) { this.heap.push(val); this.bubbleUp(); }
  pop(): number { /* swap root with last, sift down */ return this.heap.shift()!; }
}

For each structure we cover time-complexity trade-offs, real-world use cases, and a concise implementation tip in TypeScript.