Solve "Counting Change" Problem with Scala

Solve "Counting Change" Problem with Scala

/**
 * Counting Change Problem: 
 *    How many different ways can we make change of $ 1.00, given half-dollars, quarters, dimes, 
 *    nickels, and pennies? More generally, counts how many different ways you can make change 
 *    for an amount, given a list of coin denominations. For example, there are 3 ways to give 
 *    change for 4 if you have coins with denomiations 1 and 2: 1+1+1+1, 1+1+2, 2+2. 
 * 
 * A standard algorithm using recursion is described in <a href="http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-11.html#%_sec_1.2.2">Tree Recursion</a>
 * from MIT Press Book "Structure and Interpretation of Computer Programs" as:
 *    We can divide the ways to make change into two groups: 
 *    1). those ways making change without using first coin 
 *    2). those ways making change that do use the first coin, those are equivalent to all the 
 *        ways to make change for the amount (original amount - value of first coin)
 */
object CountingChange {
    def countChange(money: Int, coins: List[Int]): Int = {
	def findCombinationsCount(money: Int, coins: List[Int], coinCheckIndex: Int): Int = 
            if (money == 0) 1
                else if (money < 0) 0 // coin is bigger than remaining amount of money
                else if (coins.length == coinCheckIndex) 0 // all the coins are used
                else {
                    val usingFirstCoin = findCombinationsCount(money - coins.apply(coinCheckIndex), coins, coinCheckIndex)
                    val usingRestCoins = findCombinationsCount(money, coins, coinCheckIndex + 1)
		   
                    usingFirstCoin + usingRestCoins
                }
	  
        findCombinationsCount(money, coins, 0)
    }
  
    def main(args: Array[String]) {
        val coinList : List[Int] = List(1, 5, 10)
        	
        println("countingChange(12) is " + countChange(12, coinList))
    }
}