code.davidloor.com

Field guides

Learn enough to solve
all twenty.

Four short guides covering the language fundamentals and algorithmic patterns this site's problems exercise. Read in order or jump in. No prerequisites beyond "I can write a function."

  1. 01

    How to Think About Programs

    Before syntax. Variables as labeled boxes, functions as recipes, control flow as decisions, decomposition as the real skill. Language-agnostic.

    · fundamentals· mental-model· beginners
    16 min
  2. 02

    How Computers Represent Data

    Bits, bytes, integers, floats, characters. Why 0.1 + 0.2 ≠ 0.3, why the modulo operator is everywhere, and why arrays start at zero.

    · fundamentals· data· math
    14 min
  3. 03

    Python Foundations

    The Python you need to solve every problem in the set. Data structures, idioms, and the standard-library tools that show up in interviews.

    · python· language· basics
    18 min
  4. 04

    JavaScript Foundations

    Modern JavaScript for interview problems — let/const, Map and Set over plain objects, the sort comparator trap, and the array methods that solve most things.

    · javascript· language· basics
    18 min
  5. 05

    Algorithmic Patterns

    Ten patterns cover every problem in the set. Recognize the shape of the input and the structure of the answer follows.

    · algorithms· patterns· problem-solving
    22 min
  6. 06

    Big-O & Complexity

    How to read time and space complexity from code, the seven complexity classes you'll meet, and the hidden costs that surprise people in interviews.

    · complexity· big-o· analysis
    12 min