Solved ProjectEuler/035

ProjectEuler/035/desc.yml

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+title: How many circular primes are there below one million?
+url: http://projecteuler.net/problem=35
+
+desc: |
+  The number, 197, is called a circular prime because all rotations of the digits: 197, 971, and 719, are themselves prime.
+  There are thirteen such primes below 100: 2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, and 97.
+  How many circular primes are there below one million?
+solution: Bruteforce
+solutions:
+
+

ProjectEuler/035/solve.php

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+<?php
+define('MAX',1000000);
+
+function is_prime($prime) {    
+    $sqrt = sqrt($prime);
+    for ($i = 3; $i <= $sqrt; $i+=2){
+        if ($prime%$i == 0) return false; 
+    } 
+    return true; 
+}
+ 
+function fact($int){
+	static $facts = array(1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880);
+	return $facts[$int];
+}
+$primes = array(2);
+$primes_ordered = array(2);
+for($i=3;$i<MAX;$i+=2) {
+	if(is_prime($i)) {
+		//$primes[] = $i;
+		$temp = str_split($i);
+		sort($temp);
+		$primes_ordered[] = implode($temp);
+	}
+}
+echo "Found primes below 1mil\n";
+$result = 0;
+foreach($primes_ordered as $p) {
+	$counts = fact(strlen($p));
+	foreach($primes_ordered as $order) {
+		if($p == $order) {
+			$counts--;
+		}
+	}
+	if($counts == 0) {
+		//echo $p."\n";
+		$result++;
+	}
+}
+echo $result;