Memory Match

When this game starts, it takes a list of pairs (e.g., [Apple, Apple, Banana, Banana]) and shuffles them so they are distributed randomly across the grid.

A beginner programmer might try to shuffle an array by using the built-in sorting function: array.sort(() => Math.random() - 0.5).

This is considered a terrible practice. Sorting algorithms are designed for transitive logic (if A > B and B > C, then A > C). When you introduce randomness into a sort function, the browser's engine gets confused, resulting in an uneven distribution where some cards are statistically much more likely to stay near their original positions.

The standard computer science algorithm for shuffling an array is the Fisher-Yates Shuffle (specifically the Durstenfeld version):

1. Start at the very last card in the deck.
2. Pick a random number between 0 and the current card's index.
3. Swap the current card with the card at that random index.
4. Move to the previous card and repeat until you reach the beginning.

Because the Fisher-Yates shuffle only touches each card exactly once, its time complexity is O(N). This guarantees a perfectly uniform mathematical distribution while remaining incredibly fast, even for decks with millions of cards.