solved day 1 2015

2015/days/day1.php

@@ -0,0 +1,49 @@
+<?php
+
+// Problem: https://adventofcode.com/2015/day/1
+
+/*
+ * Solution 1
+ *
+ * Runtime: ~0.158ms
+ */
+function day1solution1() {
+  $start_time = microtime(true);
+  $instructions = file_get_contents('./inputs/day1.txt');
+  $up_floors = substr_count($instructions, "(");
+  $down_floors = substr_count($instructions, ")");
+  $total = $up_floors - $down_floors;
+  echo "The answer is $total\n";
+  $end_time = microtime(true);
+  $execution_time = ($end_time - $start_time);
+  echo $execution_time * 1000 . "\n";
+}
+
+/*
+ * Solution 1b
+ *
+ * Runtime: ~.33ms
+ */
+function day1solution1b() {
+  $start_time = microtime(true);
+  $instructions = file_get_contents('./2015/inputs/day1.txt');
+  $chars = str_split($instructions);
+  $position = 1;
+  $floor = 0;
+  foreach ($chars as $char) {
+    match ($char) {
+      "(" => $floor++,
+      ")" => $floor--,
+    };
+    if ($floor == -1) {
+      break;
+    }
+    else {
+      $position++;
+    }
+  };
+  echo "The position is $position\n";
+  $end_time = microtime(true);
+  $execution_time = ($end_time - $start_time);
+  echo $execution_time * 1000 . "\n";
+}