Restructuring

solutions/ProjectEuler/037/solve.php

@@ -0,0 +1,33 @@
+<?php
+
+$count = 0;
+$sum = 0;
+function is_prime(int $n) :bool{for($i=$n**.5|1;$i&&$n%$i--;);return!$i&&$n>1;}
+
+for ($prime = 11; $count < 11; $prime += 2) {
+    if (is_prime($prime)) {
+        //echo "Testing $prime\n";
+        for ($c = 1; $c < strlen($prime); $c++) {
+            $left = substr($prime, -$c);
+            //echo "Trimmed left $left\n";
+            if (!is_prime($left)) {
+                //echo "Not prime $left\n";
+                continue 2;
+            }
+        }
+
+        for ($c = 1; $c < strlen($prime); $c++) {
+            $right = substr($prime, 0, $c);
+            //echo "Trimmed right $right\n";
+            if (!is_prime($right)) {
+                //echo "Not prime $right\n";
+                continue 2;
+            }
+        }
+        $sum += $prime;
+        $count++;
+        echo "found $prime\n";
+    }
+}
+
+echo "Total sum: $sum\n";