From 26f76f606f7b050c4d0ace29ac79f6688c2121e8 Mon Sep 17 00:00:00 2001
From: beauvill <charles.beauville@epfl.ch>
Date: Tue, 24 Sep 2019 15:54:38 +0200
Subject: [PATCH] Created Pascal, Balance and countChange functions

---
 src/main/scala/recfun/RecFun.scala | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/main/scala/recfun/RecFun.scala b/src/main/scala/recfun/RecFun.scala
index 4a2b054..dc11b25 100644
--- a/src/main/scala/recfun/RecFun.scala
+++ b/src/main/scala/recfun/RecFun.scala
@@ -9,18 +9,36 @@ object RecFun extends RecFunInterface {
         print(s"${pascal(col, row)} ")
       println()
 
+  
+
   /**
    * Exercise 1
    */
-  def pascal(c: Int, r: Int): Int = ???
+  def pascal(c: Int, r: Int): Int = 
+    if (c == 0 || c == r) then 1 
+    else pascal(c-1,r-1) + pascal(c,r-1)
 
   /**
    * Exercise 2
    */
-  def balance(chars: List[Char]): Boolean = ???
+  def balance(chars: List[Char]): Boolean = {
+    def checkParenthesis(chars: List[Char], opened: Int): Boolean =
+      if (chars.isEmpty) then opened == 0
+      else if (opened < 0) then false
+      else if (chars.head == '(') then checkParenthesis(chars.tail, opened + 1)
+      else if (chars.head == ')') then checkParenthesis(chars.tail, opened - 1)
+      else checkParenthesis(chars.tail, opened)
+
+    checkParenthesis(chars, 0)
+  }
+    
 
   /**
    * Exercise 3
    */
-  def countChange(money: Int, coins: List[Int]): Int = ???
+  def countChange(money: Int, coins: List[Int]): Int =
+    if(money == 0) then 1
+    else if(money < 0) then 0
+    else if(coins.isEmpty) then 0
+    else countChange(money - coins.head, coins) + countChange(money, coins.tail)
 }