text: var express = require('express');
  var multer = require('multer');
  var router = express.Router();
  
  var problem_controller = require('../controllers/problem_controller');
  var upload = multer({ dest: 'tmp/' });
  
  router.get('/', problem_controller.get_problem_list);
  
  router.get('/tag/:tag', problem_controller.get_all_problem_with_tag);
  
  router.get('/diff/:diff', problem_controller.get_all_problem_with_diff);
  
  router.get('/:pid', problem_controller.get_problem);
  
  router.post('/:pid', upload.single('submit-file'), problem_controller.post_submission);
  
  router.post('/:pid/live', problem_controller.post_submission_live_editor);
  
  router.get('/:pid/clearcookie', function(req, res) {
      res.clearCookie("submitLang")
          .redirect('/problems/' + req.params.pid);
  });
  
  module.exports = router;