Ch94 (Lua): Task 1 & Task 2

6 files changed, 145 insertions, 2 deletions

diff --git a/challenge-094/tyler-wardhaugh/lua/README.md b/challenge-094/tyler-wardhaugh/lua/README.md
index 2e1e278b45..5e25cb80fd 100644
--- a/challenge-094/tyler-wardhaugh/lua/README.md
+++ b/challenge-094/tyler-wardhaugh/lua/README.md
@@ -7,11 +7,11 @@ The Weekly Challenge - #091 - Tyler Wardhaugh
 
 Run Task 1:
 
-    $ ./run.lua ch-1 N
+    $ ./run.lua ch-1 S1 S2 S3...
 
 Run Task 2:
 
-    $ ./run.lua ch-2 N1 N2 N3...
+    $ ./run.lua ch-2
 
 Run the project's tests (all the samples from the task descriptions plus some others):
 
diff --git a/challenge-094/tyler-wardhaugh/lua/ch-1.lua b/challenge-094/tyler-wardhaugh/lua/ch-1.lua
new file mode 100755
index 0000000000..36a04bd462
--- /dev/null
+++ b/challenge-094/tyler-wardhaugh/lua/ch-1.lua
@@ -0,0 +1,45 @@
+#!/usr/bin/env lua
+
+require'util'
+
+local t1 = {}
+t1.DEFAULT_INPUT = {"opt", "bat", "saw", "tab", "pot", "top", "was"}
+
+function t1.keygen(s)
+  local tbl = {}
+  s:gsub('.', function(c) table.insert(tbl, c) end)
+  table.sort(tbl)
+  return table.concat(tbl)
+end
+
+function t1.group_anagrams(coll)
+  local groups = util.group_by(t1.keygen, coll)
+
+  -- sorting for stable results (for testing)
+  table.sort(groups)
+
+  return groups
+end
+
+function t1.run(args)
+  local s
+  if #args > 0 then
+    s = args
+  else
+    s = t1.DEFAULT_INPUT
+  end
+  local groups = t1.group_anagrams(s)
+
+  local lead = ''
+  io.write('[ ')
+  for _, v in pairs(groups) do
+    table.sort(v)
+    io.write(lead .. '("')
+    io.write(table.concat(v, '", "'))
+    io.write('")')
+    lead = '  '
+  end
+  print(' ]')
+end
+
+return t1
diff --git a/challenge-094/tyler-wardhaugh/lua/ch-2.lua b/challenge-094/tyler-wardhaugh/lua/ch-2.lua
new file mode 100755
index 0000000000..37fc925e3d
--- /dev/null
+++ b/challenge-094/tyler-wardhaugh/lua/ch-2.lua
@@ -0,0 +1,51 @@
+#!/usr/bin/env lua
+
+local t2 = {}
+
+--[[
+        1
+       / \
+      2   3
+     / \
+    4   5
+       / \
+      6   7
+--]]
+t2.DEFAULT_INPUT = {1, {2, {4}, {5, {6}, {7}}}, {3}}
+
+function t2.tree_to_linked_list(tree)
+  local function _tree_to_linked_list(tree, results)
+    local val = tree[1]
+    local left = tree[2]
+    local right = tree[3]
+
+    if val then
+      table.insert(results, val)
+    end
+
+    if left then
+      _tree_to_linked_list(left, results)
+    end
+
+    if right then
+      _tree_to_linked_list(right, results)
+    end
+
+    return results
+  end
+  return _tree_to_linked_list(tree, {})
+end
+
+function t2.run(args)
+  local tree
+  if #args > 0 then
+    tree = args
+  else
+    tree = t2.DEFAULT_INPUT
+  end
+
+  local result = t2.tree_to_linked_list(tree)
+  print(table.concat(result, ' -> '))
+end
+
+return t2
diff --git a/challenge-094/tyler-wardhaugh/lua/run.lua b/challenge-094/tyler-wardhaugh/lua/run.lua
new file mode 100755
index 0000000000..c6e7473bee
--- /dev/null
+++ b/challenge-094/tyler-wardhaugh/lua/run.lua
@@ -0,0 +1,9 @@
+#!/usr/bin/env lua
+
+local filename = arg[1]
+local run_args = table.move(arg, 2, #arg, 1, {})
+
+io.write(string.format("Running task from '%s' with {%s}:\n",
+  filename, table.concat(run_args, ", ")))
+
+require(filename).run(run_args)
diff --git a/challenge-094/tyler-wardhaugh/lua/test.lua b/challenge-094/tyler-wardhaugh/lua/test.lua
new file mode 100755
index 0000000000..68a7815ded
--- /dev/null
+++ b/challenge-094/tyler-wardhaugh/lua/test.lua
@@ -0,0 +1,27 @@
+#!/usr/bin/env lua
+
+require 'busted.runner'()
+
+describe("Task 1, Group Anagrams", function()
+  local t1 = require'ch-1'
+  it("produces correct results for the examples", function()
+    assert.are.same(
+      {
+        abt={'bat', 'tab'},
+        asw={'saw', 'was'},
+        opt={'opt', 'pot', 'top'}
+      },
+      t1.group_anagrams({"opt", "bat", "saw", "tab", "pot", "top", "was"}))
+    assert.are.same({x={'x'}}, t1.group_anagrams({"x"}))
+  end)
+end)
+
+describe("Task 2, Binary Tree to Linked List", function()
+  local t2 = require'ch-2'
+  it("produces correct results for the examples", function()
+    assert.are.same(
+      { 1, 2, 4, 5, 6, 7, 3 },
+      t2.tree_to_linked_list({1, {2, {4}, {5, {6}, {7}}}, {3}})
+      )
+  end)
+end)
diff --git a/challenge-094/tyler-wardhaugh/lua/util.lua b/challenge-094/tyler-wardhaugh/lua/util.lua
new file mode 100644
index 0000000000..855b5d34fb
--- /dev/null
+++ b/challenge-094/tyler-wardhaugh/lua/util.lua
@@ -0,0 +1,11 @@
+util = {}
+
+function util.group_by(f, coll)
+  local result = {}
+  for _, v in pairs(coll) do
+    local k = f(v)
+    if not result[k] then result[k] = {} end
+    table.insert(result[k], v)
+  end
+  return result
+end