all tasks

Task/Sorting-algorithms-Pancake-sort/Ruby/sorting-algorithms-pancake-sort.rb

@@ -0,0 +1,31 @@
+class Array
+  def pancake_sort!
+    num_flips = 0
+    self.size.downto(2) do |i|
+      end_idx = i - 1
+      max_idx = self[0..end_idx].each_with_index.max_by {|e| e[0]}.last
+      next if max_idx == end_idx
+
+      if max_idx > 0
+        self[0..max_idx] = self[0..max_idx].reverse
+
+        if $DEBUG
+          num_flips += 1
+          p [num_flips, self]
+        end
+      end
+
+      self[0..end_idx] = self[0..end_idx].reverse
+
+      if $DEBUG
+        num_flips += 1
+        p [num_flips, self]
+      end
+    end
+
+    self
+  end
+end
+
+p a = (1..9).to_a.shuffle
+p a.pancake_sort!