调整

app/controllers/challenges_controller.rb

@@ -1,7 +1,7 @@
 # encoding: utf-8
 class ChallengesController < ApplicationController
   layout "base_shixun"
-  before_filter :check_authentication
+  before_filter :check_authentication, :except => [:index]
   before_filter :find_shixun, :only => [:index, :new, :create, :destroy, :challenge_build, :update_evaluation, :add_choose_question, :new_choose_question,
                                           :choose_type_show, :edit_choose_question, :update_choose_question, :destroy_challenge_choose]
   before_filter :find_challenge, :only => [:show, :edit, :update, :challenge_build, :index_up, :index_down, :destroy, :update_evaluation, :add_choose_question,