From ef1310235f3821fddd8249da65f85eb191bf2ff3 Mon Sep 17 00:00:00 2001
From: sljtheultima <sljtheultima@users.noreply.github.com>
Date: Tue, 2 Oct 2018 18:19:51 +0800
Subject: [PATCH] Ruby Quicksort

---
 Quicksort.rb | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 Quicksort.rb

diff --git a/Quicksort.rb b/Quicksort.rb
new file mode 100644
index 0000000..040a2f6
--- /dev/null
+++ b/Quicksort.rb
@@ -0,0 +1,32 @@
+def quicksort(arr, lo, hi)
+  
+  if arr.length <= 1
+    return arr
+  else
+    pivot = segment(arr, lo, hi)
+    if (lo < pivot-1)
+      quicksort(arr, lo, pivot-1)
+    end
+    if (hi > pivot)
+      quicksort(arr, pivot, hi)
+    end
+    return arr
+  end
+  
+end
+
+def segment(arr, lo, hi)
+  pivot = arr[hi]
+
+  left = lo
+  for element in (lo...hi)
+    if arr[element] <= pivot
+      arr[left], arr[element] = arr[element], arr[left]
+      left += 1
+    end
+  end
+  
+  arr[left], arr[hi] = arr[hi], arr[left]
+  return left
+  
+end