Data commit

Task/Recamans-sequence/PHP/recamans-sequence.php

@@ -0,0 +1,45 @@
+<?php
+$a = array();
+array_push($a, 0);
+
+$used = array();
+array_push($used, 0);
+
+$used1000 = array();
+array_push($used1000, 0);
+
+$foundDup = false;
+$n = 1;
+
+while($n <= 15 || !$foundDup || count($used1000) < 1001) {
+	$next = $a[$n - 1] - $n;
+	if ($next < 1 || in_array($next, $used)) {
+		$next += 2 * $n;
+	}
+	$alreadyUsed = in_array($next, $used);
+	array_push($a, $next);
+	if (!$alreadyUsed) {
+		array_push($used, $next);
+		if (0 <= $next && $next <= 1000) {
+			array_push($used1000, $next);
+		}
+	}
+	if ($n == 14) {
+		echo "The first 15 terms of the Recaman sequence are : [";
+		foreach($a as $i => $v) {
+			if ( $i == count($a) - 1)
+				echo "$v";
+			else
+				echo "$v, ";
+		}
+		echo "]\n";
+	}
+	if (!$foundDup && $alreadyUsed) {
+		printf("The first duplicate term is a[%d] = %d\n", $n, $next);
+		$foundDup = true;
+	}
+	if (count($used1000) == 1001) {
+		printf("Terms up to a[%d] are needed to generate 0 to 1000\n", $n);
+	}
+	$n++;
+}