Yoshimitakei fibonacci

fibonacci/fibonacci.rb

@@ -21,20 +21,18 @@
 # http://ruby-doc.org/core-2.1.5/doc/syntax/methods_rdoc.html
 
 class Fibonacci
-  def is_fibonacci? (n)
-	  n == 0 ? fib_number = 0  
-	  n == 1 ? fib_number = 1
-	if n > 1 
-         fib_sequence.each {|n|		
-	 fib_sequence = [ ] << fib_number = fib[n-1] + fib[n-2]
-         }
-	end
-  end
+  def is_fibonacci? (check_number)
+    fibonacci_seq = [0,1]
+    while check_number > fibonacci_seq.last
+      fib_num = fibonacci_seq[-1] + fibonacci_seq[-2]
+      fibonacci_seq.push fib_num
+    end
+    fibonacci_seq.include? check_number
+  end  
 end
-
-
 
 test = Fibonacci.new
 test.is_fibonacci?(5)
 
 
+

fibonacci/fibonacci_ken.rb

@@ -0,0 +1,59 @@
+# Original solution
+# class Fibonacci
+#   def is_fibonacci?(n)
+#     fib_ary = [0,1]
+#     return true if fib_ary.include?(n)
+#     
+#     while n >= get_fibonacci(fib_ary)
+#       return true if n == get_fibonacci(fib_ary)
+#       fib_ary << get_fibonacci(fib_ary)
+#     end
+# 
+#     false
+#   end
+# 
+#   private 
+#   
+#   def get_fibonacci(a)
+#     a[-1] + a[-2]
+#   end
+# end
+
+#rv means return value
+# http://ruby.bastardsbook.com/chapters/enumerables/
+
+# First iteration of inject solution:
+# # class Fibonacci
+#   def is_fibonacci?(n)
+#     #rv means return value
+#     # http://ruby.bastardsbook.com/chapters/enumerables/
+#     n.times.inject([0,1]) { |rv, e| rv << rv[-2] + rv[-1] }.include?(n)
+#   end
+# end
+#
+# require 'pry'
+
+# Second iteration of inject solution:
+class Fibonacci
+  def is_fibonacci?(n)
+    return true if n == 0
+    n.times.inject([0,1]) do |rv, e| 
+      return true if rv.include?(n)
+      break if rv.last > n
+      rv << rv[-2] + rv[-1] 
+    end
+    false
+  end
+end
+f = Fibonacci.new
+p f.is_fibonacci?(144)
+
+
+
+# showing inject method
+# cool = [48, 46, 14, 15, 5, 99].inject(0) do |rv, e|
+#   binding.pry
+#   rv + e
+# end
+# 
+# p cool