Ships.swift

import UIKit

enum State {
    case go
    case stay
}

func calculateGroupCompatibility(groupName: String, shipName: String) -> State {
    var dict: [String: Int] = [:]
    
    "abcdefghijklmnopqrstuvwxyz"
        .enumerated()
        .map {  (index, value) -> (String, Int) in
            return (String(value), index)
        }
        .forEach { pair in
            dict[pair.0] = pair.1 + 1
        }
        
    
    var totalGroup = 1
    var totalShip = 1
    groupName
        .map { String($0) }
        .forEach { item in
            totalGroup = dict[item]! * totalGroup
        }
    
    shipName
        .map { String($0) }
        .forEach { item in
            totalShip = dict[item]! * totalShip
        }
    
    return groupName == shipName ? .go : .stay
}


calculateGroupCompatibility(groupName: "caca", shipName: "caca")