Data commit

Task/Sorting-algorithms-Merge-sort/Lua/sorting-algorithms-merge-sort-1.lua

@@ -0,0 +1,56 @@
+local function merge(left_container, left_container_begin, left_container_end, right_container, right_container_begin, right_container_end, result_container, result_container_begin, comparator)
+	while left_container_begin <= left_container_end do
+		if right_container_begin > right_container_end then
+			for i = left_container_begin, left_container_end do
+				result_container[result_container_begin] = left_container[i]
+				result_container_begin = result_container_begin + 1
+			end
+
+			return
+		end
+
+		if comparator(right_container[right_container_begin], left_container[left_container_begin]) then
+			result_container[result_container_begin] = right_container[right_container_begin]
+			right_container_begin = right_container_begin + 1
+		else
+			result_container[result_container_begin] = left_container[left_container_begin]
+			left_container_begin = left_container_begin + 1
+		end
+
+		result_container_begin = result_container_begin + 1
+	end
+
+	for i = right_container_begin, right_container_end do
+		result_container[result_container_begin] = right_container[i]
+		result_container_begin = result_container_begin + 1
+	end
+end
+
+local function mergesort_impl(container, container_begin, container_end, comparator)
+	local range_length = (container_end - container_begin) + 1
+	if range_length < 2 then return end
+	local copy = {}
+	local copy_len = 0
+
+	for it = container_begin, container_end do
+		copy_len = copy_len + 1
+		copy[copy_len] = container[it]
+	end
+
+	local middle = bit.rshift(range_length, 1) -- or math.floor(range_length / 2)
+	mergesort_impl(copy, 1, middle, comparator)
+	mergesort_impl(copy, middle + 1, copy_len, comparator)
+	merge(copy, 1, middle, copy, middle + 1, copy_len, container, container_begin, comparator)
+end
+
+local function mergesort_default_comparator(a, b)
+	return a < b
+end
+
+function table.mergesort(container, comparator)
+	if not comparator then
+		comparator = mergesort_default_comparator
+	end
+
+	mergesort_impl(container, 1, #container, comparator)
+end

Task/Sorting-algorithms-Merge-sort/Lua/sorting-algorithms-merge-sort-2.lua

@@ -0,0 +1,22 @@
+function getLower(a,b)
+  local i,j=1,1
+  return function()
+    if not b[j] or a[i] and a[i]<b[j] then
+      i=i+1; return a[i-1]
+    else
+      j=j+1; return b[j-1]
+    end
+  end
+end
+
+function merge(a,b)
+  local res={}
+  for v in getLower(a,b) do res[#res+1]=v end
+  return res
+end
+
+function mergesort(list)
+  if #list<=1 then return list end
+  local s=math.floor(#list/2)
+  return merge(mergesort{unpack(list,1,s)}, mergesort{unpack(list,s+1)})
+end