Add Days 1 & 2

cema-sp · cema-sp · commit ad8f98ded0eb · 2017-12-02T22:32:30.000-08:00
diff --git a/01.exs b/01.exs
@@ -0,0 +1,136 @@
+defmodule Puzzle do
+  def sum(string, delta \\ 1)
+
+  def sum("", _), do: 0
+  def sum(<<_ :: utf8 >>, _), do: 0
+  def sum(string, 0), do: string
+
+  def sum(string, delta) do
+    shifted = rotate(string, delta)
+
+    sum_(string, shifted)
+  end
+
+  def sum_mid(string) do
+    delta = div byte_size(string), 2
+    sum(string, delta)
+  end
+
+  defp sum_("", ""), do: 0
+  defp sum_(string, shifted) do
+    { a, rest_string } = String.next_grapheme(string)
+    { b, rest_shifted } = String.next_grapheme(shifted)
+
+    inc = if a == b, do: String.to_integer(a), else: 0
+    inc + sum_(rest_string, rest_shifted)
+  end
+
+  defp rotate("", _), do: ""
+  defp rotate(string, 0), do: string
+
+  defp rotate(<<head :: utf8>>, _), do: <<head :: utf8>>
+
+  defp rotate(<<head :: utf8, rest :: binary >>, shift) do
+    rotate(<< rest :: binary, head >>, shift - 1)
+  end
+end
+
+mode = List.first(System.argv)
+
+if mode == "test" do
+  ExUnit.start()
+
+  defmodule PuzzleTest do
+    use ExUnit.Case
+
+    describe "sum(string)" do
+      test "empty string" do
+        sum = Puzzle.sum("")
+        assert sum == 0
+      end
+
+      test "22" do
+        sum = Puzzle.sum("22")
+        assert sum == 4
+      end
+
+      test "23" do
+        sum = Puzzle.sum("23")
+        assert sum == 0
+      end
+
+      test "1122" do
+        sum = Puzzle.sum("1122")
+        assert sum == 3
+      end
+
+      test "1111" do
+        sum = Puzzle.sum("1111")
+        assert sum == 4
+      end
+
+      test "1234" do
+        sum = Puzzle.sum("1234")
+        assert sum == 0
+      end
+
+      test "91212129" do
+        sum = Puzzle.sum("91212129")
+        assert sum == 9
+      end
+    end
+
+    describe "sum_mid(string)" do
+      test "empty string" do
+        sum = Puzzle.sum_mid("")
+        assert sum == 0
+      end
+
+      test "22" do
+        sum = Puzzle.sum_mid("22")
+        assert sum == 4
+      end
+
+      test "23" do
+        sum = Puzzle.sum_mid("23")
+        assert sum == 0
+      end
+
+      test "1122" do
+        sum = Puzzle.sum_mid("1122")
+        assert sum == 0
+      end
+
+      test "1212" do
+        sum = Puzzle.sum_mid("1212")
+        assert sum == 6
+      end
+
+      test "1221" do
+        sum = Puzzle.sum_mid("1221")
+        assert sum == 0
+      end
+
+      test "123425" do
+        sum = Puzzle.sum_mid("123425")
+        assert sum == 4
+      end
+
+      test "123123" do
+        sum = Puzzle.sum_mid("123123")
+        assert sum == 12
+      end
+
+      test "12131415" do
+        sum = Puzzle.sum_mid("12131415")
+        assert sum == 4
+      end
+    end
+  end
+else
+  data = File.read!("01.txt") |> String.trim_trailing
+  sum = Puzzle.sum(data)
+  sum_mid = Puzzle.sum_mid(data)
+  IO.puts "The sum is: #{sum}"
+  IO.puts "The sum mid is: #{sum_mid}"
+end
diff --git a/01.txt b/01.txt
@@ -0,0 +1 @@
+3294199471327195994824832197564859876682638188889768298894243832665654681412886862234525991553276578641265589959178414218389329361496673991614673626344552179413995562266818138372393213966143124914469397692587251112663217862879233226763533911128893354536353213847122251463857894159819828724827969576432191847787772732881266875469721189331882228146576832921314638221317393256471998598117289632684663355273845983933845721713497811766995367795857965222183668765517454263354111134841334631345111596131682726196574763165187889337599583345634413436165539744188866156771585647718555182529936669683581662398618765391487164715724849894563314426959348119286955144439452731762666568741612153254469131724137699832984728937865956711925592628456617133695259554548719328229938621332325125972547181236812263887375866231118312954369432937359357266467383318326239572877314765121844831126178173988799765218913178825966268816476559792947359956859989228917136267178571776316345292573489873792149646548747995389669692188457724414468727192819919448275922166321158141365237545222633688372891451842434458527698774342111482498999383831492577615154591278719656798277377363284379468757998373193231795767644654155432692988651312845433511879457921638934877557575241394363721667237778962455961493559848522582413748218971212486373232795878362964873855994697149692824917183375545192119453587398199912564474614219929345185468661129966379693813498542474732198176496694746111576925715493967296487258237854152382365579876894391815759815373319159213475555251488754279888245492373595471189191353244684697662848376529881512529221627313527441221459672786923145165989611223372241149929436247374818467481641931872972582295425936998535194423916544367799522276914445231582272368388831834437562752119325286474352863554693373718848649568451797751926315617575295381964426843625282819524747119726872193569785611959896776143539915299968276374712996485367853494734376257511273443736433464496287219615697341973131715166768916149828396454638596713572963686159214116763
diff --git a/02.exs b/02.exs
@@ -0,0 +1,113 @@
+defmodule Puzzle do
+  def checksum(""), do: 0
+
+  def checksum(spreadsheet) do
+    spreadsheet
+      |> String.split("\n", trim: true)
+      |> Enum.map(&minmax/1)
+      |> Enum.map(
+           fn { nil, nil } -> 0
+              { min, max } -> max - min
+           end
+         )
+      |> Enum.sum
+  end
+
+  def checksum_div(""), do: 0
+
+  def checksum_div(spreadsheet) do
+    spreadsheet
+      |> String.split("\n", trim: true)
+      |> Enum.map(&divides/1)
+      |> Enum.map(
+           fn [{ nil, nil }] -> 0
+              [{ divided, divider }] -> div(divided, divider)
+           end
+         )
+      |> Enum.sum
+  end
+
+  defp minmax(""), do: { nil, nil }
+  defp minmax(row) do
+    row
+      |> String.split
+      |> Enum.map(&String.to_integer/1)
+      |> Enum.reduce(
+           { nil, nil },
+           fn(digit, acc) ->
+             cond do
+               is_nil(elem(acc, 0)) ->
+                 { digit, digit }
+               digit < elem(acc, 0) ->
+                 put_elem(acc, 0, digit)
+               digit > elem(acc, 1) ->
+                 put_elem(acc, 1, digit)
+               true ->
+                 acc
+             end
+           end
+         )
+  end
+
+  defp divides(""), do: { nil, nil }
+  defp divides(row) do
+    ints = row |> String.split |> Enum.map(&String.to_integer/1)
+    for a <- ints,
+        b <- ints,
+        a > b,
+        rem(a, b) == 0,
+        do: { a, b }
+  end
+end
+
+mode = List.first(System.argv)
+
+if mode == "test" do
+  ExUnit.start()
+
+  defmodule PuzzleTest do
+    use ExUnit.Case
+
+    describe "checksum(spreadsheet)" do
+      test "for 3 lines" do
+        spreadsheet = """
+        5 1 9 5
+        7 5 3
+        2 4 6 8
+        """
+
+        checksum = Puzzle.checksum(spreadsheet)
+        assert checksum == 18
+      end
+
+      test "for 2 lines with eq values" do
+        spreadsheet = """
+        5 5
+        5 5
+        """
+
+        checksum = Puzzle.checksum(spreadsheet)
+        assert checksum == 0
+      end
+    end
+
+    describe "checksum_div(spreadsheet)" do
+      test "for 3 lines" do
+        spreadsheet = """
+        5 9 2 8
+        9 4 7 3
+        3 8 6 5
+        """
+
+        checksum = Puzzle.checksum_div(spreadsheet)
+        assert checksum == 9
+      end
+    end
+  end
+else
+  data = File.read!("02.txt") |> String.trim_trailing
+  checksum = Puzzle.checksum(data)
+  checksum_div = Puzzle.checksum_div(data)
+  IO.puts "The checksum is: #{checksum}"
+  IO.puts "The checksum div is: #{checksum_div}"
+end
diff --git a/02.txt b/02.txt
@@ -0,0 +1,16 @@
+104	240	147	246	123	175	372	71	116	230	260	118	202	270	277	292
+740	755	135	205	429	822	844	90	828	115	440	805	526	91	519	373
+1630	991	1471	1294	52	1566	50	1508	1367	1489	55	547	342	512	323	51
+1356	178	1705	119	1609	1409	245	292	1434	694	405	1692	247	193	1482	1407
+2235	3321	3647	212	1402	3711	3641	1287	2725	692	1235	3100	123	144	104	101
+1306	1224	1238	186	751	734	1204	1275	366	149	1114	166	1118	239	153	943
+132	1547	1564	512	2643	2376	2324	2159	1658	107	1604	145	2407	131	2073	1878
+1845	91	1662	108	92	1706	1815	1797	1728	1150	1576	83	97	547	1267	261
+78	558	419	435	565	107	638	173	93	580	338	52	633	256	377	73
+1143	3516	4205	3523	148	401	3996	3588	300	1117	2915	1649	135	134	182	267
+156	2760	1816	2442	2985	990	2598	1273	167	821	138	141	2761	2399	1330	1276
+3746	3979	2989	161	4554	156	3359	173	3319	192	3707	264	762	2672	4423	2924
+3098	4309	4971	5439	131	171	5544	595	154	571	4399	4294	160	6201	4329	5244
+728	249	1728	305	2407	239	691	2241	2545	1543	55	2303	1020	753	193	1638
+260	352	190	877	118	77	1065	1105	1085	1032	71	87	851	56	1161	667
+1763	464	182	1932	1209	640	545	931	1979	197	1774	174	2074	1800	939	161

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	`1`	+3294199471327195994824832197564859876682638188889768298894243832665654681412886862234525991553276578641265589959178414218389329361496673991614673626344552179413995562266818138372393213966143124914469397692587251112663217862879233226763533911128893354536353213847122251463857894159819828724827969576432191847787772732881266875469721189331882228146576832921314638221317393256471998598117289632684663355273845983933845721713497811766995367795857965222183668765517454263354111134841334631345111596131682726196574763165187889337599583345634413436165539744188866156771585647718555182529936669683581662398618765391487164715724849894563314426959348119286955144439452731762666568741612153254469131724137699832984728937865956711925592628456617133695259554548719328229938621332325125972547181236812263887375866231118312954369432937359357266467383318326239572877314765121844831126178173988799765218913178825966268816476559792947359956859989228917136267178571776316345292573489873792149646548747995389669692188457724414468727192819919448275922166321158141365237545222633688372891451842434458527698774342111482498999383831492577615154591278719656798277377363284379468757998373193231795767644654155432692988651312845433511879457921638934877557575241394363721667237778962455961493559848522582413748218971212486373232795878362964873855994697149692824917183375545192119453587398199912564474614219929345185468661129966379693813498542474732198176496694746111576925715493967296487258237854152382365579876894391815759815373319159213475555251488754279888245492373595471189191353244684697662848376529881512529221627313527441221459672786923145165989611223372241149929436247374818467481641931872972582295425936998535194423916544367799522276914445231582272368388831834437562752119325286474352863554693373718848649568451797751926315617575295381964426843625282819524747119726872193569785611959896776143539915299968276374712996485367853494734376257511273443736433464496287219615697341973131715166768916149828396454638596713572963686159214116763