ScalaWeek1

week1.scala

// Excercise 1
def pascal(c: Int, r: Int): Int = 
  if (c == 0 || r == c) 1 else pascal(c - 1, r - 1) + pascal(c, r - 1)

// Excercise 2
def balance(chars: List[Char]): Boolean = {

  def loop(i: Int, amountOpen: Int): Boolean =
    if (i >= chars.size) amountOpen == 0
    else if (amountOpen < 0) false
    else if (chars(i).equals('(')) loop(i + 1, amountOpen + 1)
    else if (chars(i).equals(')')) loop(i + 1, amountOpen - 1)
    else loop(i + 1, amountOpen)
  
  loop(0, 0)
}

//Exercise 3
def countChange(money: Int, coins: List[Int]): Int ={
  if (money < 0 || coins.isEmpty)
    0
  else if (money == 0)
    1
  else
    countChange(money - coins.head, coins) + countChange(money, coins.tail)
}

//Excercise 4
def factorial(n: Int): Int = 
  if (n == 0) 1 else n * factorial(n-1)