title: Maximum Distance Two Occurrences Element Array
signature: class Solution {
  
      public int MaximumDistanceTwoOccurrencesElementArray(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(int actual, int expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(List<int> arr, int n, int expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                int 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>{1, 20, 25, 28, 29, 31, 34, 35, 38, 39, 41, 43, 46, 55, 56, 60, 65, 66, 74, 77, 79, 80, 81, 83, 84, 88, 88, 88, 90, 91, 99}, 27, 
                  1
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{26, 14, 56, 84, -56, -84, -98, 12, -78, 18, -42, 58, 46, -66, -46, 66, 98, 34, -16, 8, -20, 66, 74, 26, 42, -84, 38, 86, 14, 86, 26, -42, -30, 6, -54, -76, -66, 18, 58, 66, 74, -62, 8, -42, 62, -14, -90, 98, -24}, 34, 
                  30
              );
              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}, 11, 
                  10
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{69, 87}, 1, 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{-98, -88, -86, -62, -52, -26, -24, -20, -12, 6, 8, 26, 36, 40, 42, 54, 68, 72, 84, 92, 94, 98, 98}, 12, 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0}, 29, 
                  28
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{11, 16, 17, 19, 20, 21, 21, 22, 27, 37, 45, 49, 64, 77, 81, 85, 96}, 9, 
                  1
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{-20, 0, 18, -96}, 2, 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 22, 
                  20
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );result = runner.driver(
                  new List<int>{54, 5, 98, 71, 9, 34, 60, 28, 58, 66, 28, 45, 4}, 10, 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-9...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def maximum_distance_two_occurrences_element_array(arr, n):
      mp = {
          
      }
      maxDict = 0
      for i in range(n):
          if (arr[i] not in mp.keys()):
              mp[arr[i]] = i
          else:
              maxDict = max(maxDict, (i - mp[arr[i]]))
      return maxDict
source_cpp: int maximum_distance_two_occurrences_element_array(vector<int> arr, int n) {
    unordered_map < int, int > mp;
    int max_dist = 0;
    for ( int i = 0;
    i < n;
    i ++ ) {
      if ( mp . find ( arr [ i ] ) == mp . end ( ) ) mp [ arr [ i ] ] = i;
      else max_dist = max ( max_dist, i - mp [ arr [ i ] ] );
    }
    return max_dist;
  }