Restructuring

solutions/ProjectEuler/045/solve.php

@@ -0,0 +1,47 @@
+<?php
+/**
+ * Triangle   Tn = n*(n+1)/2
+ * Pentagonal Pn = n*(3n-1)/2
+ * Hexagonal  Hn = n*(2n-1)
+ * T(285) = P(165) = H(143) = 40755
+ * Find next
+ */
+
+function Tn($n)
+{
+    return $n*($n+1)/2;
+}
+
+function Pn($n)
+{
+    return $n*(3*$n-1)/2;
+}
+
+function Hn($n)
+{
+    return $n*(2*$n-1);
+}
+
+echo "Tn(285)=".Tn(285).PHP_EOL;
+echo "Pn(165)=".Pn(165).PHP_EOL;
+echo "Hn(143)=".Hn(143).PHP_EOL;
+
+
+for($t = 285; $t < 100000; $t++) 
+{
+    $triangle[$t] = Tn($t);
+}
+
+for($p = 165; $p < 100000; $p++) 
+{
+    $pentagonal[$p] = Pn($p);
+}
+
+for($h = 143; $h < 100000; $h++) 
+{
+    $hexagonal[$h] = Hn($h);
+}
+
+$result = array_intersect($triangle, $pentagonal, $hexagonal);
+
+print_r($result);