implement Task 2 in Lua

3 files changed, 40 insertions, 0 deletions

diff --git a/challenge-078/tyler-wardhaugh/lua/README.md b/challenge-078/tyler-wardhaugh/lua/README.md
index 741ee6bff1..91e2f8575d 100644
--- a/challenge-078/tyler-wardhaugh/lua/README.md
+++ b/challenge-078/tyler-wardhaugh/lua/README.md
@@ -9,6 +9,10 @@ Run Task 1:
 
     $ lua -e 'require"ch-1".run({9, 10, 7, 5, 6, 1})'
 
+Run Task 2:
+
+    $ lua -e 'require"ch-2".run({10, 20, 30, 40, 50}, {3, 4})'
+
 Run the project's tests (which are samples from the task descriptions):
 
     $ lua test.lua
diff --git a/challenge-078/tyler-wardhaugh/lua/ch-2.lua b/challenge-078/tyler-wardhaugh/lua/ch-2.lua
new file mode 100755
index 0000000000..f5b2ab901a
--- /dev/null
+++ b/challenge-078/tyler-wardhaugh/lua/ch-2.lua
@@ -0,0 +1,22 @@
+#!/usr/bin/env lua
+
+local t2 = {}
+
+function t2.multi_rotate(list, rotations)
+  local rts = {}
+  for _, rv in ipairs(rotations) do
+    local rotated = table.move(list, rv + 1, #list, 1, {})
+    for i = 1, rv do table.insert(rotated, list[i]) end
+    table.insert(rts, rotated)
+  end
+  return rts
+end
+
+function t2.run(...)
+  local res = t2.multi_rotate(...)
+  for _, v in ipairs(res) do
+    print('[' .. table.concat(v, ' ') .. ']')
+  end
+end
+
+return t2
diff --git a/challenge-078/tyler-wardhaugh/lua/test.lua b/challenge-078/tyler-wardhaugh/lua/test.lua
index d47309f705..c5494095c0 100755
--- a/challenge-078/tyler-wardhaugh/lua/test.lua
+++ b/challenge-078/tyler-wardhaugh/lua/test.lua
@@ -9,3 +9,17 @@ describe("Task 1, Leader Elements", function()
     assert.are.same({5}, t1.leaders({3, 4, 5}))
   end)
 end)
+
+describe("Task 2, Left Rotation", function()
+  local t2  = require'ch-2'
+  it("produces correct results for the examples", function()
+    assert.are.same(
+      {{40, 50, 10, 20, 30}, {50, 10, 20, 30, 40}},
+      t2.multi_rotate({10, 20, 30, 40, 50}, {3, 4})
+    )
+    assert.are.same(
+      {{4, 2, 6, 3, 7}, {6, 3, 7, 4, 2}, {3, 7, 4, 2, 6}},
+      t2.multi_rotate({7, 4, 2, 6, 3}, {1, 3, 4})
+    )
+  end)
+end)