import Foundation

class Node : CustomStringConvertible {
    var value: Int
    var next: Node?
    init(_ value: Int, next: Node? = nil) {
        self.value = value
        self.next = next
    }
    var description: String {
        let nextStr = if let next { String(describing: next) } else { "nil" }
        return "(\(value))->\(nextStr)"
    }
    func evolve() -> Int {
        if value == 0 {
            value = 1
            return 1
        }
        // I don't have log10() unless I import Graphics, which is overkill...
        let s = String(value)
        if s.count.isMultiple(of: 2) {
            let secondHalf = s.count/2 ..< s.count
            let newNode = Node(Int(String(Array(s)[secondHalf]))!, next: next)
            value = Int(String(Array(s)[0 ..< s.count/2]))!
            next = newNode
            return 2
        }
        value = value*2024
        return 1
    }
}

func readInput(_ filePath: String) throws -> Node {
    let content = try String(contentsOfFile: filePath, encoding: .ascii)
        .trimmingCharacters(in: .whitespacesAndNewlines)
    let head: Node = Node(-1)
    var current = head
    content.split(separator: " ").forEach { i in
        print(i)
        let new = Node(Int(i)!)
        current.next = new
        current = new
    }
    return head.next!
}

func evolve(_ chain: Node) -> Int {
    var next: Node? = chain
    var count = 0
    while let node = next {
        next = node.next
        count += node.evolve()
    }
    return count
}

let nums = try readInput(CommandLine.arguments[1])
print(nums)
for i in 1...25 {
    let count = evolve(nums)
    print("\(i): \(count)")  // - \(nums)")
}