title: Non Repeating Element
signature: fun nonRepeatingElement(arr: ArrayList<Int>, n: Int): Int {
test_code: package main
  
  import kotlin.text.*
  import kotlin.math.*
  
  
  // SOLUTION CODE
  // ===================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE
  // ===================================
  fun validateSolution(actual:Int, expected:Int):Boolean{
    return actual.equals(expected)
  }
  fun driver(arr: ArrayList<Int>, n: Int, expected:Int):String {
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME(arr, n), expected)) {
                return "PASSED"
        }
        return "FAILED"
      } catch (e: Exception){
        return e::class.simpleName as String
      }
  
  }
  
  fun main() {
      var result: String = ""
      result = driver(arrayListOf(1, 2, 3, 4, 6, 6, 7, 9, 10, 13, 16, 23, 30, 32, 36, 42, 42, 43, 44, 47, 48, 48, 49, 52, 52, 53, 55, 56, 58, 59, 60, 60, 63, 67, 68, 68, 74, 75, 76, 80, 81, 81, 83, 83, 86, 87, 91, 92, 97), 47, 1)
      println("TEST-0...${result}")
      
      result = driver(arrayListOf(-96, -46, -86, 56, -72, 50, 18, 8, 50), 8, -96)
      println("TEST-1...${result}")
      
      result = driver(arrayListOf(0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1), 14, -1)
      println("TEST-2...${result}")
      
      result = driver(arrayListOf(19, 10, 49, 40, 34, 21, 63, 51), 5, 19)
      println("TEST-3...${result}")
      
      result = driver(arrayListOf(-96, -96, -90, -88, -88, -84, -80, -76, -68, -64, -64, -52, -52, -52, -52, -50, -50, -48, -48, -40, -32, -26, -24, -22, -20, -14, -12, 0, 6, 8, 10, 20, 24, 28, 34, 36, 54, 60, 60, 60, 68, 74, 74, 74, 84, 88, 94), 27, -90)
      println("TEST-4...${result}")
      
      result = driver(arrayListOf(1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0), 19, -1)
      println("TEST-5...${result}")
      
      result = driver(arrayListOf(1, 2, 3, 10, 15, 21, 28, 36, 41, 44, 45, 47, 72, 77, 77, 79, 85), 15, 1)
      println("TEST-6...${result}")
      
      result = driver(arrayListOf(42, -84, 42, 36, -10, 24, -62, 60), 7, -84)
      println("TEST-7...${result}")
      
      result = driver(arrayListOf(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, 1, 1, 1, 1, 1), 35, -1)
      println("TEST-8...${result}")
      
      result = driver(arrayListOf(2, 21, 42, 92, 65, 62, 75, 43, 81, 17, 92, 86, 37, 63, 27, 97, 24, 61, 85, 49, 84, 7, 14, 19, 60, 55, 68, 79, 8, 12, 75, 12, 92, 79, 42), 27, 2)
      println("TEST-9...${result}")
      
          
  }
  
  main()
source_py: def non_repeating_element(arr, n):
      for i in range(n):
          j = 0
          while (j < n):
              if ((i != j) and (arr[i] == arr[j])):
                  break
              j += 1
          if (j == n):
              return arr[i]
      return (- 1)
source_cpp: int non_repeating_element(vector<int> arr, int n) {
    for ( int i = 0;
    i < n;
    i ++ ) {
      int j;
      for ( j = 0;
      j < n;
      j ++ ) if ( i != j && arr [ i ] == arr [ j ] ) break;
      if ( j == n ) return arr [ i ];
    }
    return - 1;
  }