Solved ProjectEuler/023: php

ProjectEuler/023/solve.php

@@ -0,0 +1,27 @@
+<?php
+function abundant($input) {
+	$max = floor(sqrt($input));
+	$sum = 1;
+	for($div=2;$div<=$max ;$div++) {
+		if($input % $div == 0) {
+			$sum += ($input/$div != $div) ? $input/$div + $div : $div;
+			if($sum > $input)
+				return true;
+		}
+	}
+	return false;
+}
+//Find all abundant numbers
+for($number = 12; $number <= 28123 ; $number++) {
+	if(abundant($number)) { $adjnum[] = $number; }
+}
+
+$sum = array_sum(range(1,23));
+for($test = 24; $test <= 20162; $test++) {
+	$nadundant = true;
+	for($index = 0; $adjnum[$index] < $test; $index++) {
+		if(abundant($test - $adjnum[$index])) {$nadundant = false; break; }
+	}
+	if($nadundant) {$sum += $test; }
+}
+echo $sum;