[2017-12-02] Solutions for both puzzles

Makefile

@@ -4,6 +4,8 @@ day1:
 	php day1/main.php
 
 day2:
+	php day2/main.php
+
 day3:
 day4:
 day5:

day2/main.php

@@ -0,0 +1,52 @@
+<?php
+// https://adventofcode.com/2017/day/2
+
+function puzzle1(string $input) : int
+{
+    $rows = explode(PHP_EOL, $input);
+    $sum = 0;
+
+    foreach ($rows as $row) {
+        $columns = explode("\t", $row);
+
+        sort($columns);
+
+        $small = array_shift($columns);
+        $big = array_pop($columns);
+
+        $sum += ($big - $small);
+    }
+
+    return $sum;
+}
+
+function puzzle2(string $input) : int
+{
+    $rows = explode(PHP_EOL, $input);
+    $sum = 0;
+
+    foreach ($rows as $row) {
+        $columns = explode("\t", $row);
+
+        foreach ($columns as $key1 => $value1) {
+            foreach ($columns as $key2 => $value2) {
+                if ($key1 === $key2) {
+                    continue;
+                }
+
+                if ($value1 < $value2) {
+                    continue;
+                }
+
+                // Do the actual division
+                $div = $value1 / $value2;
+
+                if (intval($div) === $div) {
+                    $sum += $div;
+                }
+            }
+        }
+    }
+
+    return $sum;
+}