让用户可以看diff

web/reinfo.php

@@ -24,7 +24,7 @@ if(!isset($_GET['sid'])){
 function is_valid($str2){
   global $_SESSION,$OJ_NAME,$OJ_FRIENDLY_LEVEL;
   if(isset($_SESSION[$OJ_NAME.'_'.'source_browser'])) return true;
-    //return true; // 如果希望能让任何人都查看对比和RE,放开行首注释，并设定$OJ_SHOW_DIFF=true; if you fail to view diff , try remove the // at beginning of this line.
+    return true; // 如果希望能让任何人都查看对比和RE,放开行首注释，并设定$OJ_SHOW_DIFF=true; if you fail to view diff , try remove the // at beginning of this line.
   if($OJ_FRIENDLY_LEVEL>3) return true;
   
   $n = strlen($str2);