🎉 Hello world

day_2/part_2.php

@@ -0,0 +1,46 @@
+<?php
+
+$input = explode(',', file_get_contents('input.txt'));
+
+function run_opcode(array $input)
+{
+    $i = 0;
+    while ($input[$i] !== 99) {
+        [$operation, $first, $second, $position] = array_slice($input, $i, 4);
+        switch ($operation) {
+            case 1:
+                $input[$position] = $input[$first] + $input[$second];
+                break;
+            case 2:
+                $input[$position] = $input[$first] * $input[$second];
+                break;
+            case 99:
+                return $input[0];
+            default:
+                echo 'unknown operation : '.$operation;
+                exit;
+        }
+        $i += 4;
+    }
+
+    return $input[0];
+}
+
+$noun = 0;
+$verb = 0;
+while ($verb !== 99) {
+    $noun = 0;
+    while ($noun !== 99) {
+        $clone_input = $input;
+        $clone_input[1] = $noun;
+        $clone_input[2] = $verb;
+        $magic_number = run_opcode($clone_input);
+        if ($magic_number === 19690720) {
+            echo sprintf('noun : %s | verb : %s', $noun, $verb);
+        }
+        $noun++;
+    }
+    $verb++;
+}
+
+echo sprintf("\n".'answer : %u', ((100*$noun)+$verb));