Towers of Hanoi in Scala
This solution for the Towers of Hanoi game in Scala is a good start, but there are some improvements that can be made to make it more idiomatic and functional. Here are a few suggestions: 1. Avoid using mutable variables: In functional programming, it is generally recommended to avoid using mutable variables whenever possible. Instead of using a mutable variable `i` to keep track of the tower index, you can use the `zipWithIndex` method to iterate over the towers with their indices. This way, you can directly pattern match on the tower index in the fold function. 2. Use pattern matching: Scala has powerful pattern matching capabilities that can make your code more concise and easier to read. Instead of using if-else conditions to check the tower index, you can use pattern matching to match on the tower indices and perform the necessary operations. 3. Use functional composition: Instead of manually constructing the new list of towers using `:::` and `List`, you can use functional composition to combine the transformation functions. For example, you can use `map` to transform each tower and use `updated` to replace the old tower with the updated one. Here's an improved version of the `Move` method that incorporates these suggestions: ```scala def move(from: Int, to: Int, towers: List[List[Int]]): List[List[Int]] = { if (!canMove(from, to, towers)) { println("Can't move there") return towers } val disk = towers(from).head towers.zipWithIndex.map { case (tower, i) if i == from => tower.tail case (tower, i) if i == to => List(disk) ::: tower case (tower, _) => tower } } ``` In this version, we use pattern matching to match on the tower index and perform the necessary operations. The `zipWithIndex` method returns a tuple with the element and its index, which can be pattern matched using `(tower, i)`. Then, we use `map` to transform each tower based on the pattern match. By making these changes, the code becomes more functional and easier to understand. It leverages the immutability of Scala data structures and takes advantage of pattern matching and functional composition to make the code more concise and expressive.