✨ Add day 10 part 1

day_10/functions.php

@@ -0,0 +1,44 @@
+<?php
+
+
+/**
+ * @param array $array
+ * @return array|bool
+ */
+function array_flatten(array $array) {
+    return iterator_to_array(array_flatten_iterator($array), false);
+}
+
+/**
+ * @param array $array
+ * @return Generator
+ */
+function array_flatten_iterator(array $array) {
+    foreach ($array as $value) {
+        if (is_array($value)) {
+            yield from array_flatten_iterator($value);
+        } else {
+            yield $value;
+        }
+    }
+}
+
+/**
+ * @param int $x1
+ * @param int $y1
+ * @param int $x2
+ * @param int $y2
+ *
+ * @return array
+ */
+function getPointsBetween(int $x1, int $y1, int $x2, int $y2)
+{
+    $dx = $x2-$x1;
+    $dy = $y2-$y1;
+    $max = max(abs($dx), abs($dy));
+    for($t = 0; $t<=$max; $t++) {
+        $points[] = sprintf('%s,%s', $x1+($t*$dx)/$max, $y1+($t*$dy)/$max);
+    }
+
+    return $points;
+}