From edfb942e89b2a733e8321252a9ac6c31a6933696 Mon Sep 17 00:00:00 2001
From: Lucidiot <lucidiot@protonmail.com>
Date: Mon, 23 Nov 2020 01:40:56 +0100
Subject: [PATCH] 2015 day 16

---
 2015/16/sue.lua | 67 +++++++++++++++++++++++++++++++++++++++++++++++++
 README.md       |  2 +-
 2 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 2015/16/sue.lua

diff --git a/2015/16/sue.lua b/2015/16/sue.lua
new file mode 100644
index 0000000..7f6724f
--- /dev/null
+++ b/2015/16/sue.lua
@@ -0,0 +1,67 @@
+#!/usr/bin/env lua
+--[[
+This cursed script generates SQL statements to be sent to a SQLite database
+and returns two lines with two aunt IDs, for each part of the puzzle.
+
+Usage: lua5.3 part1.lua <input | sqlite3
+--]]
+
+local sues = {}
+
+for line in io.lines() do
+    local _, data_start, i = line:find('^Sue (%d+): ')
+    i = tonumber(i)
+    sues[i] = {}
+    for key, value in line:sub(data_start):gmatch('(%w+): (%d+)') do
+        sues[i][key] = tonumber(value)
+    end
+end
+
+local compounds = {
+    {name='children', expected=3, operator='='},
+    {name='cats', expected=7, operator='>'},
+    {name='samoyeds', expected=2, operator='='},
+    {name='pomeranians', expected=3, operator='<'},
+    {name='akitas', expected=0, operator='='},
+    {name='vizslas', expected=0, operator='='},
+    {name='goldfish', expected=5, operator='<'},
+    {name='trees', expected=3, operator='>'},
+    {name='cars', expected=2, operator='='},
+    {name='perfumes', expected=1, operator='='},
+}
+
+local columns = {}
+for _, compound in pairs(compounds) do
+    table.insert(columns, compound.name .. ' INTEGER')
+end
+
+print(string.format('CREATE TABLE sue (id INTEGER NOT NULL PRIMARY KEY, %s);', table.concat(columns, ", ")))
+
+local values = {}
+for i, sue in pairs(sues) do
+    local value = {i}
+    for _, compound in pairs(compounds) do
+        table.insert(value, sue[compound.name] or 'NULL')
+    end
+    table.insert(values, string.format('(%s)', table.concat(value, ', ')))
+end
+
+print(string.format('INSERT INTO sue VALUES %s;', table.concat(values, ', ')))
+
+-- Part 1 uses only the '=' operator (exact match), but part 2 uses ranges depending on the compound
+local function build_conditions(operator_override)
+    local conditions = {}
+    for _, compound in pairs(compounds) do
+        table.insert(conditions, string.format(
+            '(%s IS NULL OR %s %s %d)',
+            compound.name,
+            compound.name,
+            operator_override or compound.operator,
+            compound.expected
+        ))
+    end
+    return conditions
+end
+
+print(string.format('SELECT id FROM sue WHERE %s;', table.concat(build_conditions('='), ' AND ')))
+print(string.format('SELECT id FROM sue WHERE %s;', table.concat(build_conditions(), ' AND ')))
diff --git a/README.md b/README.md
index c7161af..74e3dc6 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ My solutions to the Advent of Code puzzles.
 13       ██
 14 ██    ██
 15       ██
-16       ██
+16 ██    ██
 17       ██
 18       ██
 19