Merge pull request #80 from zjhzxhz/master

Fix bugs for comparing outputs with Wrong Answer and Presentation Error status

judgelib.php

@@ -158,7 +158,9 @@ protected function diff() {
                     return ONLINEJUDGE_STATUS_WRONG_ANSWER;
                 $tok = strtok(" \n\r\t");
             }
-
+            if ($tok !== false) {
+                return ONLINEJUDGE_STATUS_WRONG_ANSWER;
+            }
             return ONLINEJUDGE_STATUS_PRESENTATION_ERROR;
         }
     }