title: Check Exist Two Elements Array Whose Sum Equal Sum Rest Array
signature: class Solution {
  
      public bool CheckExistTwoElementsArrayWhoseSumEqualSumRestArray(List<int> arr, int 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(bool actual, bool expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(List<int> arr, int n, bool expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                bool pred_result = solution_cls.PLACEHOLDER_FN_NAME(arr, 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(
                  new List<int>{2, 11, 5, 1, 4, 7}, 6, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{2, 4, 2, 1, 11, 15}, 6, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 13, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{69, 6, 24, 30, 75, 37, 61, 76, 19, 18, 90, 9, 49, 24, 58, 97, 18, 85, 24, 93, 71, 98, 92, 59, 75, 75, 75, 70, 35, 58, 50, 1, 64, 66, 33}, 18, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{-94, -94, -92, -74, -60, -58, -56, -44, -42, -40, -28, -14, 2, 4, 14, 20, 24, 28, 40, 42, 42, 66, 78, 78, 80, 82, 96}, 26, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1}, 10, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{21, 26, 26, 27, 61, 62, 96}, 6, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{-54, 86, 20, 26}, 3, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 4, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{44, 35, 26, 15, 56, 6, 36, 53, 15, 66, 20, 53, 99, 96, 51, 12, 61, 19, 79, 40, 99, 42, 86, 8, 11, 54, 93, 46, 23, 47, 41, 26, 66, 5, 86, 52, 64, 51, 4, 21, 63, 14, 7, 53, 31, 8, 9, 63}, 31, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-9...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def check_exist_two_elements_array_whose_sum_equal_sum_rest_array(arr, n):
      s = set()
      sum = 0
      for i in range(n):
          sum += arr[i]
      if ((sum % 2) != 0):
          return False
      sum = (sum / 2)
      for i in range(n):
          val = (sum - arr[i])
          if (arr[i] not in s):
              s.add(arr[i])
          if (val in s):
              print('Pair elements are', arr[i], 'and', int(val))
source_cpp: bool check_exist_two_elements_array_whose_sum_equal_sum_rest_array(vector<int> arr, int n) {
    int sum = 0;
    for ( int i = 0;
    i < n;
    i ++ ) sum += arr [ i ];
    if ( sum % 2 != 0 ) return false;
    sum = sum / 2;
    unordered_set < int > s;
    for ( int i = 0;
    i < n;
    i ++ ) {
      int val = sum - arr [ i ];
      if ( s . find ( val ) != s . end ( ) ) {
        return true;
      }
      s . insert ( arr [ i ] );
    }
    return false;
  }