Natalia Kuleniuk Recursion Writing Exercise

recursion-writing.rb

@@ -0,0 +1,54 @@
+def factorial(n)
+  if n == 0
+    return n
+  else
+    return n * factorial(n-1)
+  end
+end
+
+def reverse(s)
+  if s.length == 1
+    return s
+  else
+    return s[-1] + reverse(s[0...-1])
+  end
+end
+
+def bunny(n)
+  if n == 0
+    return 0
+  else
+    return 2 + bunny(n-1)
+
+  end
+end
+
+def nested(s)
+  if s.length % 2 != 0
+    return false
+  elsif s.length == 0
+    return true
+  elsif s[0] == "(" && s[-1] == ")"
+    return nested(s[1...-1])
+  else
+    return false
+  end
+end
+
+def fib(n)
+  if n == 1 || n == 0
+    return n
+  else
+    return fib(n-1) + fib(n-2)
+  end
+end
+
+def pal(s)
+  if s.length <= 1
+    return true
+  elsif s[0] == s[-1]
+    return pal(s[1...-1])
+  else
+    return false
+  end
+end