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Raahaao Code: Logic & Problem Solving

Learn to think like a programmer before, and while, you code.

9+ hours of lessons · 2 projects · €35

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What you'll learn, floor by floor

  1. 1

    Thinking in steps (Beginner)

    • What programmers actually do
    • Breaking problems down
    • Patterns and abstraction
  2. 2

    Decisions (Beginner)

    • True or false
    • Making decisions
    • Edge cases: test the edges
  3. 3

    Repetition (Intermediate)

    • Loops: doing it again
    • Accumulating and counting
    • Off-by-one and loop bugs
  4. 4

    Organising ideas (Intermediate)

    • Functions as named ideas
    • Lists as collections
    • Dictionaries as lookup
  5. 5

    Problem-solving strategies (Job-ready)

    • Work backwards and simplify
    • Brute force, then smarter
    • Recursion, gently
    • Debugging as a method

The two rooftop projects

Vending machine

Build a small vending machine by turning its rules into clear steps. You will calculate change with a limited set of coin values, decide whether an item can be bought, and connect those decisions to a text menu.

  • make_change(price_cents, paid_cents) returns a dictionary mapping each non-zero coin value in cents to its count, using the fewest coins from 200, 100, 50, 20, 10, and 5; it raises ValueError when payment is below price or the change is not representable.
  • can_buy(stock, item, paid) returns True only when item exists in stock, its quantity is positive, paid covers its price, and any change due is representable by the listed coins.
  • run_menu(stock) reads buy <item> <paid_cents>, stock, and quit commands from stdin; a successful buy reduces quantity by one and every command prints the exact response specified in the brief.

Puzzle solver

Build a small Sudoku solver that checks a 4×4 puzzle, finds the next blank, and fills a valid solution. You will break the puzzle rules into checks for rows, columns, and 2×2 boxes, then use backtracking: try a number, continue solving, and undo the choice if it leads to a dead end.

  • valid(grid) accepts only valid 4×4 Sudoku grids with values 0–4, where 0 means blank and no nonzero digit repeats in any row, column, or 2×2 box
  • next_empty(grid) returns the first blank cell as a (row, column) pair, or None when the grid is full
  • solve(grid) fills a solvable grid in place and returns True, or leaves an unsolvable grid unchanged and returns False
  • count_solutions(grid) returns the number of solutions, stopping once it reaches 2, and does not change the supplied grid
  • pretty_print(grid) returns a readable string with four rows, separating each pair of columns with a vertical bar

Questions

Do I need to install anything?

No. Everything runs in your browser. For the projects you can also work on your own computer and upload your files.

Can I skip what I already know?

Yes. Once you own a tower, each floor has a skip test: score 8 out of 10 and that floor opens.

What is the refund policy?

Refunds within 5 days of purchase. After 5 days, no refunds or returns.

Do I keep access?

Yes. A tower you buy is yours, with no subscription.

Refund policy

The towers

HTML & CSS · JavaScript · Python · SQL · C++ · Node.js · Python for Data · Flask · Algorithms & Data Structures · Java · Machine Learning · Building with AI