Ch88 (Lua): Tasks 1 & 2

4 files changed, 150 insertions, 0 deletions

diff --git a/challenge-088/tyler-wardhaugh/lua/ch-1.lua b/challenge-088/tyler-wardhaugh/lua/ch-1.lua
new file mode 100755
index 0000000000..f1f1ac675b
--- /dev/null
+++ b/challenge-088/tyler-wardhaugh/lua/ch-1.lua
@@ -0,0 +1,40 @@
+#!/usr/bin/env lua
+
+local t1 = {}
+
+function t1.array_of_product(coll)
+  local product = 1
+  for i=2,#coll do product = product * coll[i] end
+
+  local result = {product}
+  for i=2,#coll do
+    product = product // coll[i] * coll[i-1]
+    table.insert(result, product)
+  end
+  return result
+end
+
+function t1.run(arg)
+  local N = {}
+  for _, v in ipairs(arg) do table.insert(N, tonumber(v)) end
+
+  M = t1.array_of_product(N)
+
+  io.write('@M = ( ')
+  io.write(table.concat(M, ', '))
+  print(' )\n')
+
+  for i, v in ipairs(M) do
+    io.write('$M[' .. i-1 .. '] = ')
+    local temp = {}
+    for j, vv in ipairs(N) do
+      if j ~= i then
+        table.insert(temp, vv)
+      end
+    end
+    io.write(table.concat(temp, ' x '))
+    print(' = ' .. v)
+  end
+end
+
+return t1
diff --git a/challenge-088/tyler-wardhaugh/lua/ch-2.lua b/challenge-088/tyler-wardhaugh/lua/ch-2.lua
new file mode 100755
index 0000000000..4f708ae420
--- /dev/null
+++ b/challenge-088/tyler-wardhaugh/lua/ch-2.lua
@@ -0,0 +1,55 @@
+#!/usr/bin/env lua
+
+local t2 = {}
+local util = require'util'
+
+function t2.reverse(coll)
+  local result = {}
+  for i=#coll,1,-1 do table.insert(result, coll[i]) end
+  return result
+end
+
+function t2.transpose(matrix)
+    local result = {}
+    for i=1,#matrix[1] do
+        result[i] = {}
+        for j=1,#matrix do
+            result[i][j] = matrix[j][i]
+        end
+    end
+    return result
+end
+
+function t2.rotate(matrix)
+  local rotated = t2.reverse(t2.transpose(matrix))
+  return rotated
+end
+
+function t2.spiral(matrix)
+  local spiral_aux
+  spiral_aux = function(matrix, result)
+    if next(matrix) then
+      table.move(matrix[1], 1, #matrix[1], #result+1, result)
+      if #matrix > 2 then
+        table.remove(matrix, 1)
+        return spiral_aux(t2.rotate(matrix), result)
+      else
+        local reversed = t2.reverse(matrix[2])
+        table.move(reversed, 1, #reversed, #result+1, result)
+        return result
+      end
+    else
+      return result
+    end
+  end
+  return spiral_aux(matrix, {})
+end
+
+function t2.run(args)
+  local filename = args[1]
+  local matrix = util.parse_matrix_file(filename)
+  local spiraled = t2.spiral(matrix)
+  util.print_matrix({spiraled}, ', ')
+end
+
+return t2
diff --git a/challenge-088/tyler-wardhaugh/lua/test.lua b/challenge-088/tyler-wardhaugh/lua/test.lua
new file mode 100755
index 0000000000..7e3080b2ea
--- /dev/null
+++ b/challenge-088/tyler-wardhaugh/lua/test.lua
@@ -0,0 +1,24 @@
+#!/usr/bin/env lua
+
+require 'busted.runner'()
+MATRIX_FILE_PREFIX = '../clojure/resources/matrix-'
+
+describe("Task 1, Array of Product", function()
+  local t1 = require'ch-1'
+  it("produces correct results for the examples", function()
+    assert.are.same({24, 60, 120, 30, 40}, t1.array_of_product({5, 2, 1, 4, 3}))
+    assert.are.same({12, 24, 6, 8}, t1.array_of_product({2, 1, 4, 3}))
+  end)
+end)
+
+describe("Task 2, Spiral Matrix", function()
+  local t2 = require'ch-2'
+  local util = require'util'
+  local helper = function(n)
+    return t2.spiral(util.parse_matrix_file(MATRIX_FILE_PREFIX .. n))
+  end
+  it("produces correct results for the examples", function()
+    assert.are.same({1, 2, 3, 6, 9, 8, 7, 4, 5}, helper('1'))
+    assert.are.same({1, 2, 3, 4, 8, 12, 16, 15, 14, 13, 9, 5, 6, 7, 11, 10}, helper('2'))
+  end)
+end)
diff --git a/challenge-088/tyler-wardhaugh/lua/util.lua b/challenge-088/tyler-wardhaugh/lua/util.lua
new file mode 100644
index 0000000000..2602cfe69b
--- /dev/null
+++ b/challenge-088/tyler-wardhaugh/lua/util.lua
@@ -0,0 +1,31 @@
+#!/usr/bin/env lua
+
+local util = {}
+
+function util.parse_matrix_file(filename)
+  local file = io.open(filename)
+  io.input(file)
+
+  local matrix = {}
+  for line in io.lines() do
+    local row = {}
+    for d in string.gmatch(line, '%d+') do
+      table.insert(row, math.tointeger(d))
+    end
+    table.insert(matrix, row)
+  end
+
+  return matrix
+end
+
+function util.print_matrix(matrix, sep)
+  sep = sep or ' '
+  for _, row in ipairs(matrix) do
+    io.write('[ ')
+    io.write(table.concat(row, sep))
+    io.write(' ]')
+    print()
+  end
+end
+
+return util