Adding medium/hard puzzles & challenges...

challenges/2013-05-28/question2.php

@@ -0,0 +1,76 @@
+<?php
+
+<?php
+$lines = (int) fgets(STDIN);
+$seqs  = array();
+
+for ($i = 0; $i < $lines; $i++) {
+    $seq = fgets(STDIN);
+    $seq = trim($seq);
+    $seqs[] = $seq;
+}
+
+function merge_strings($base, $append, $offset, $length) {
+    if ($offset > 0) {
+
+    }
+
+}
+
+function simplifySeq($sequences, $n = 0)
+{
+    if (1 == count($sequences)) {
+        return $sequences[0];
+    }
+
+    if ($n == count($sequences)) {
+        $base = array_pop($sequences);
+        $sequences[0] .= $base;
+        return simplifySeq($sequences);
+    }
+
+    $base = array_pop($sequences);
+    $len  = strlen($base);
+
+    $mergeDone = false;
+    for ($l = $len; $l > 0; $l--) {
+        $part = substr($base, 0, $l);
+        foreach ($sequences as &$seq) {
+            $seqPart = substr($seq, -$l);
+            if ($seqPart == $part) {
+                $seq .= substr($base, $l);
+                $mergeDone = true;
+                break;
+            }
+        }
+        if ($mergeDone) {
+            break;
+        }
+    }
+
+    if (!$mergeDone) {
+        array_unshift($sequences, $base);
+        return simplifySeq($sequences, $n+1);
+    }
+
+    return simplifySeq($sequences);
+}
+
+function cleanShortSeqs($seqs)
+{
+    $c = count($seqs);
+    for ($i = 0; $i < $c; $i++) {
+        foreach ($seqs as $j => $seq) {
+            if ($i != $j && strstr($seq, $seqs[$i])) {
+                unset($seqs[$i]);
+                break;
+            }
+        }
+    }
+    return array_values($seqs);
+}
+
+$seqs   = cleanShortSeqs($seqs);
+$result = simplifySeq($seqs);
+echo strlen($result);
+