From fdbc03caf01271b299f57105e6fd29b620d2bdb5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C8=98tefan-Iulian=20Alecu?=
 <165364995+pascalecu@users.noreply.github.com>
Date: Wed, 13 May 2026 22:38:34 +0300
Subject: [PATCH] Add Zeckendorf in Ruby

---
 archive/r/ruby/zeckendorf.rb | 52 ++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 archive/r/ruby/zeckendorf.rb

diff --git a/archive/r/ruby/zeckendorf.rb b/archive/r/ruby/zeckendorf.rb
new file mode 100644
index 000000000..d6dce06c8
--- /dev/null
+++ b/archive/r/ruby/zeckendorf.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+USAGE = "Usage: please input a non-negative integer"
+
+def usage!
+  warn USAGE
+  exit 1
+end
+
+def parse_input(str)
+  usage! if str.nil? || str.strip.empty?
+
+  n = Integer(str)
+  usage! if n < 0
+
+  n
+rescue ArgumentError, NoMethodError
+  usage!
+end
+
+def fibs_upto(n)
+  fibs = [1, 2]
+  fibs << fibs[-1] + fibs[-2] while fibs[-1] <= n
+  fibs.pop if fibs[-1] > n
+  fibs
+end
+
+def zeckendorf(n)
+  return [] if n == 0
+
+  fibs = fibs_upto(n)
+  result = []
+
+  i = fibs.length - 1
+
+  while n > 0
+    if fibs[i] <= n
+      result << fibs[i]
+      n -= fibs[i]
+      i -= 2
+    else
+      i -= 1
+    end
+  end
+
+  result
+end
+
+input = ARGV.first
+n = parse_input(input)
+
+puts zeckendorf(n).join(", ")