title: Nth Even Length Palindrome
signature: class Solution {
  
      public string NthEvenLengthPalindrome(string n) {
test_code: using System;
  using System.Numerics;
  using System.Diagnostics;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Security.Cryptography;
  using System.Web.UI;
  using System.Web.Script.Serialization;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  namespace EvaluatePrediction {
      class TestRunner {
          public bool ValidateSolution(string actual, string expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(string n, string expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                string pred_result = solution_cls.PLACEHOLDER_FN_NAME(n); 
                if (ValidateSolution(
                      pred_result,
                      expected)){
                  return "PASSED";
                }
                return "FAILED";
              } 
              catch (Exception exception_obj)
              {
                return exception_obj.GetType().FullName;
              }
          }
          static void Main(string[] args) {
              TestRunner runner = new TestRunner();
              String result;
              result = runner.driver(
                  "lSUhEvxcgfI", 
                  "lSUhEvxcgfIIfgcxvEhUSl"
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  "77329283", 
                  "7732928338292377"
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  "010111111", 
                  "010111111111111010"
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  "Stazb", 
                  "StazbbzatS"
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  "0702", 
                  "07022070"
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  "01111111", 
                  "0111111111111110"
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  "a", 
                  "aa"
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  "rznb", 
                  "rznbbnzr"
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def nth_even_length_palindrome(n):
      res = n
      for j in range((len(n) - 1), (- 1), (- 1)):
          res += n[j]
      return res
source_cpp: string nth_even_length_palindrome(string n) {
    string res = n;
    for ( int j = n . length ( ) - 1;
    j >= 0;
    -- j ) res += n [ j ];
    return res;
  }