Code Explainers

Code explainers tagged #data-structures

go 
package scheduler
 
import (
	"container/heap"

A priority job queue with Go's container/heap

priority-queue heap interfaces
Intermediate 9 steps
php 
<?php
 
namespace App\Queue;
 

A stable priority job queue in PHP

priority-queue data-structures closures
Intermediate 8 steps
php 
final class BitmapGrid
{
    private SplFixedArray $cells;
 

A flat-array bitmap grid in PHP

data-structures row-major-order bitmap
Intermediate 7 steps
ruby 
class LRUCache
  def initialize(capacity)
    raise ArgumentError, "capacity must be positive" unless capacity.positive?
 

How an LRU cache works in Ruby

caching eviction hash-ordering
Intermediate 7 steps
ruby 
class QueryParser
  def self.parse(query_string)
    new(query_string).parse
  end

Parsing nested query strings in Ruby

parsing recursion tokenization
Intermediate 9 steps
javascript 
class HistoryStack {
  constructor(initial = '', limit = 100) {
    this.past = [];
    this.present = initial;

Building an undo/redo history stack

undo-redo state-management debouncing
Intermediate 7 steps
python 
from collections import OrderedDict
from typing import Any, Hashable, Optional
 
 

Building an LRU cache with OrderedDict

caching eviction data-structures
Intermediate 6 steps
php 
<?php
 
function buildTree(array $items, ?int $parentId = null): array
{

Building a tree from a flat list in PHP

recursion tree grouping
Intermediate 6 steps
typescript 
export class PriorityQueue<T> {
  private heap: Array<{ value: T; priority: number }> = [];
 
  get size(): number {

Building a binary-heap priority queue in TypeScript

binary-heap priority-queue generics
Intermediate 9 steps
go 
package cache
 
import (
	"container/list"

Building a generic LRU cache in Go

lru-cache generics linked-list
Intermediate 8 steps
java 
public class UnionFind {
    private final int[] parent;
    private final int[] rank;
    private int count;

How union-find with path compression works

disjoint-set path-compression union-by-rank
Intermediate 7 steps
javascript 
class Stack {
  #items = [];
 
  push(value) {

Building a Stack with private fields

data-structures encapsulation iterators
Intermediate 7 steps
python 
from collections import Counter
 
 
def word_frequencies(text):

Counting things with collections.Counter

counting multiset data-structures
Beginner 8 steps
ruby 
class LinkedList
  include Enumerable
 
  Node = Struct.new(:value, :next_node)

Building an enumerable linked list in Ruby

linked-list enumerable data-structures
Intermediate 7 steps
typescript 
class LRUCache<K, V> {
  private readonly capacity: number;
  private readonly map: Map<K, V>;
 

Building an LRU cache on a JS Map

caching data-structures generics
Intermediate 8 steps